1.
North America
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North America is a continent entirely within the Northern Hemisphere and almost all within the Western Hemisphere. It can also be considered a subcontinent of the Americas. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the west and south by the Pacific Ocean, and to the southeast by South America and the Caribbean Sea. North America covers an area of about 24,709,000 square kilometers, about 16. 5% of the land area. North America is the third largest continent by area, following Asia and Africa, and the fourth by population after Asia, Africa, and Europe. In 2013, its population was estimated at nearly 565 million people in 23 independent states, or about 7. 5% of the worlds population, North America was reached by its first human populations during the last glacial period, via crossing the Bering land bridge. The so-called Paleo-Indian period is taken to have lasted until about 10,000 years ago, the Classic stage spans roughly the 6th to 13th centuries. The Pre-Columbian era ended with the migrations and the arrival of European settlers during the Age of Discovery. Present-day cultural and ethnic patterns reflect different kind of interactions between European colonists, indigenous peoples, African slaves and their descendants, European influences are strongest in the northern parts of the continent while indigenous and African influences are relatively stronger in the south. Because of the history of colonialism, most North Americans speak English, Spanish or French, the Americas are usually accepted as having been named after the Italian explorer Amerigo Vespucci by the German cartographers Martin Waldseemüller and Matthias Ringmann. Vespucci, who explored South America between 1497 and 1502, was the first European to suggest that the Americas were not the East Indies, but a different landmass previously unknown by Europeans. In 1507, Waldseemüller produced a map, in which he placed the word America on the continent of South America. He explained the rationale for the name in the accompanying book Cosmographiae Introductio, for Waldseemüller, no one should object to the naming of the land after its discoverer. He used the Latinized version of Vespuccis name, but in its feminine form America, following the examples of Europa, Asia and Africa. Later, other mapmakers extended the name America to the continent, In 1538. Some argue that the convention is to use the surname for naming discoveries except in the case of royalty, a minutely explored belief that has been advanced is that America was named for a Spanish sailor bearing the ancient Visigothic name of Amairick. Another is that the name is rooted in a Native American language, the term North America maintains various definitions in accordance with location and context. In Canadian English, North America may be used to refer to the United States, alternatively, usage sometimes includes Greenland and Mexico, as well as offshore islands
2.
North American F-100 Super Sabre
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The North American F-100 Super Sabre was an American supersonic jet fighter aircraft that served with the United States Air Force from 1954 to 1971 and with the Air National Guard until 1979. The first of the Century Series of USAF jet fighters, it was the first USAF fighter capable of speed in level flight. The F-100 was designed by North American Aviation as a higher performance follow-on to the F-86 Sabre air superiority fighter, adapted as a fighter bomber, the F-100 was supplanted by the Mach two class F-105 Thunderchief for strike missions over North Vietnam. The F-100 flew extensively over South Vietnam as the air forces primary close air support jet until being replaced by the more efficient subsonic LTV A-7 Corsair II, the F-100 also served in other NATO air forces and with other U. S. allies. In its later life, it was referred to as the Hun. In January 1951, North American Aviation delivered an unsolicited proposal for a day fighter to the United States Air Force. Named Sabre 45 because of its 45° wing sweep, it represented an evolution of the F-86 Sabre, the mockup was inspected on 7 July 1951, and after over a hundred modifications, the new aircraft was accepted as the F-100 on 30 November 1951. Extensive use of titanium throughout the aircraft was notable, on 3 January 1952, the USAF ordered two prototypes followed by 23 F-100As in February and an additional 250 F-100As in August. The YF-100A first flew on 25 May 1953, seven ahead of schedule. It reached Mach 1.04 in spite of being fitted with a de-rated XJ57-P-7 engine, the second prototype flew on 14 October 1953, followed by the first production F-100A on 9 October 1953. These findings were confirmed during Project Hot Rod operational suitability tests. Particularly troubling was the yaw instability in certain regimes of flight which produced inertia coupling, the aircraft could develop a sudden yaw and roll which would happen too fast for the pilot to correct and would quickly over-stress the aircraft structure to disintegration. It was under conditions that North Americans chief test pilot. Another control problem stemmed from handling characteristics of the wing at high angles of attack. As the aircraft approached stall speeds, loss of lift on the tips of the caused an violent pitch-up. This particular phenomenon became known as the Sabre dance, nevertheless, delays in the Republic F-84F Thunderstreak program pushed the Tactical Air Command to order the raw F-100A into service. Tactical Air Command also requested that future F-100s be fighter-bombers, with the capability of delivering nuclear bombs, the North American F-107 was a follow-on Mach 2 development of the F-100 with the air intake moved above and behind the cockpit. It was not produced in quantity in favor of the Republic F-105 Thunderchief, the F-100A officially entered USAF service on 27 September 1954, with the 479th Fighter Wing at George AFB, California
3.
Incendiary device
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Napalm for example, is petroleum especially thickened with certain chemicals into a gel to slow, but not stop, combustion, releasing energy over a longer time frame than an explosive device. In the case of napalm, the gel adheres to surfaces, the first incendiary devices to be dropped during World War I fell on coastal towns in the south west of England on the night of 18–19 January 1915. The small number of German bombs, also known as firebombs, were finned containers filled with kerosene and oil and they were dropped from Zeppelin airships. On 8 September 1915, Zeppelin L-13 dropped a number of firebombs. They did, however, have an effect on the morale of the civilian population of the United Kingdom. After further experiments with 5-litre barrels of benzol, in 1918, a further advantage of the alloy casing was its lightness, being a quarter of the density of steel, which meant that each bomber could carry a considerable number. The hope was that the two capitals would be engulfed in a blaze, causing the Allies to sue for peace. The Royal Air Force had already used their own Baby Incendiary Bomb which also contained a thermite charge, Incendiary bombs were used extensively in World War II as an effective bombing weapon, often in a conjunction with high-explosive bombs. Probably the most famous incendiary attacks are the bombing of Dresden, different methods of delivery, e. g. small bombs, bomblet clusters and large bombs, were tested and implemented. For example, a bomb casing was filled with small sticks of incendiary. An explosive charge would then ignite the material, often starting a raging fire. The fire would burn at temperatures that could destroy most buildings made of wood or other combustible materials. Less successful was the Flammenbombe, a 250 kg or 500 kg high explosive bomb case filled with an inflammable oil mixture, nevertheless, the civilian destruction caused by such weapons quickly earned them a reputation as terror weapons with the targeted populations. The Nazi regime began the campaign of incendiary bombings at the start of World War II with the bombing of Warsaw, and continued with the London Blitz and the bombing of Moscow, among other cities. Later, an extensive reprisal was exacted by the Allies in the bombing campaign that lead to the annihilation of many German cities. Sixty-seven Japanese cities lost significant areas to incendiary attacks, the most deadly single bombing raid in all history was Operation Meetinghouse, an incendiary attack that killed some 100,000 Tokyo residents in one night. The 4 lb incendiary bomb, developed by ICI, was the standard light incendiary bomb used by RAF Bomber Command in very large numbers and it was the weapon of choice for the British dehousing plan. The bomb consisted of a body made from aluminium-magnesium alloy with a cast iron/steel nose
4.
Gasoline
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Gasoline /ˈɡæsəliːn/, known as petrol /ˈpɛtrəl/ outside North America, is a transparent, petroleum-derived liquid that is used primarily as a fuel in internal combustion engines. It consists mostly of organic compounds obtained by the distillation of petroleum. On average, a 42-gallon barrel of oil yields about 19 US gallons of gasoline when processed in an oil refinery. The characteristic of a gasoline blend to resist igniting too early is measured by its octane rating. Gasoline is produced in several grades of octane rating, sometimes, gasoline also contains ethanol as an alternative fuel, for economic or environmental reasons. Gasoline, as used worldwide in the vast number of combustion engines used in transport and industry, has a significant impact on the environment. Gasoline may also enter the environment uncombusted, as liquid and as vapors, from leakage and handling during production, transport and delivery, from tanks, from spills. As an example of efforts to control leakage, many storage tanks are required to have extensive measures in place to detect. Gasoline contains benzene and other known carcinogens, Gasoline inhalation can produce an intense high, however the practice is thought to cause severe organ damage, including mental retardation. The first automotive combustion engines, so-called Otto engines, were developed in the last quarter of the 19th century in Germany, the fuel was a relatively volatile hydrocarbon obtained from coal gas. With a boiling point near 85 °C, it was suited for early carburetors. The development of a spray nozzle carburetor enabled the use of less volatile fuels, further improvements in engine efficiency were attempted at higher compression ratios, but early attempts were blocked by knocking. In the 1920s, antiknock compounds were introduced by Thomas Midgley Jr. and Boyd and this innovation started a cycle of improvements in fuel efficiency that coincided with the large-scale development of oil refining to provide more products in the boiling range of gasoline. In the 1950s oil refineries started to focus on high octane fuels, the 1970s witnessed greater attention to the environmental consequences of burning gasoline. These considerations led to the out of TEL and its replacement by other antiknock compounds. Subsequently, low-sulfur gasoline was introduced, in part to preserve the catalysts in modern exhaust systems, Gasoline is the term that is used in North America to refer to the most popular automobile fuel. The Oxford English Dictionary dates the first use to 1863, when it was spelled gasolene and it was never a trademark, although it may have been derived from older trademarks such as Cazeline and Gazeline. Variant spellings of gasoline had been used to refer to raw petroleum since the 16th century, Petrol is the preferred term in most Commonwealth countries
5.
Diesel fuel
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Diesel engines have found broad use as a result of higher thermodynamic efficiency and thus fuel efficiency. This is particularly noted where diesel engines are run at part-load, as their air supply is not throttled as in a petrol engine, to distinguish these types, petroleum-derived diesel is increasingly called petrodiesel. Ultra-low-sulfur diesel is a standard for defining diesel fuel with substantially lowered sulfur contents, as of 2016, almost all of the petroleum-based diesel fuel available in UK, Europe and North America is of a ULSD type. In the UK, diesel fuel for use is commonly abbreviated DERV, standing for diesel-engined road vehicle. In Australia diesel fuel is known as distillate, and in Indonesia, it is known as Solar. Diesel fuel originated from experiments conducted by German scientist and inventor Rudolf Diesel for his engine he invented in 1892. Diesel fuel is produced from various sources, the most common being petroleum, other sources include biomass, animal fat, biogas, natural gas, and coal liquefaction. Petroleum diesel, also called petrodiesel, or fossil diesel is the most common type of diesel fuel, synthetic diesel can be produced from any carbonaceous material, including biomass, biogas, natural gas, coal and many others. The raw material is gasified into synthesis gas, which after purification is converted by the Fischer–Tropsch process to a synthetic diesel, the process is typically referred to as biomass-to-liquid, gas-to-liquid or coal-to-liquid, depending on the raw material used. Paraffinic synthetic diesel generally has a content of sulfur and very low aromatics content, reducing unregulated emissions of toxic hydrocarbons, nitrous oxides. Fatty-acid methyl ester, more known as biodiesel, is obtained from vegetable oil or animal fats which have been transesterified with methanol. It can be produced from many types of oils, the most common being rapeseed oil in Europe, methanol can also be replaced with ethanol for the transesterification process, which results in the production of ethyl esters. FAME can be used pure in engines where the manufacturer approves such use, FAME as a fuel is specified in DIN EN14214 and ASTM D6751. Pure biodiesel has an energy content about 5–10% lower than petroleum diesel, the loss in power when using pure biodiesel is 5–7%. As FAME contains low levels of sulfur, the emissions of oxides and sulfates. Use of biodiesel also results in reductions of unburned hydrocarbons, carbon monoxide, CO emissions using biodiesel are substantially reduced, on the order of 50% compared to most petrodiesel fuels. The exhaust emissions of particulate matter from biodiesel have been found to be 30% lower than overall particulate matter emissions from petrodiesel, the exhaust emissions of total hydrocarbons are up to 93% lower for biodiesel than diesel fuel. Biodiesel also may reduce risks associated with petroleum diesel
6.
Aluminium
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Aluminium or aluminum is a chemical element in the boron group with symbol Al and atomic number 13. It is a silvery-white, soft, nonmagnetic, ductile metal, Aluminium metal is so chemically reactive that native specimens are rare and limited to extreme reducing environments. Instead, it is combined in over 270 different minerals. The chief ore of aluminium is bauxite, Aluminium is remarkable for the metals low density and its ability to resist corrosion through the phenomenon of passivation. Aluminium and its alloys are vital to the industry and important in transportation and structures, such as building facades. The oxides and sulfates are the most useful compounds of aluminium, despite its prevalence in the environment, no known form of life uses aluminium salts metabolically, but aluminium is well tolerated by plants and animals. Because of these salts abundance, the potential for a role for them is of continuing interest. Aluminium is a soft, durable, lightweight, ductile. It is nonmagnetic and does not easily ignite, a fresh film of aluminium serves as a good reflector of visible light and an excellent reflector of medium and far infrared radiation. The yield strength of aluminium is 7–11 MPa, while aluminium alloys have yield strengths ranging from 200 MPa to 600 MPa. Aluminium has about one-third the density and stiffness of steel and it is easily machined, cast, drawn and extruded. Aluminium atoms are arranged in a cubic structure. Aluminium has an energy of approximately 200 mJ/m2. Aluminium is a thermal and electrical conductor, having 59% the conductivity of copper. Aluminium is capable of superconductivity, with a critical temperature of 1.2 kelvin. Aluminium is the most common material for the fabrication of superconducting qubits, the strongest aluminium alloys are less corrosion resistant due to galvanic reactions with alloyed copper. This corrosion resistance is reduced by aqueous salts, particularly in the presence of dissimilar metals. In highly acidic solutions, aluminium reacts with water to form hydrogen, primarily because it is corroded by dissolved chlorides, such as common sodium chloride, household plumbing is never made from aluminium
7.
Harvard University
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Although never formally affiliated with any denomination, the early College primarily trained Congregationalist and Unitarian clergy. Its curriculum and student body were gradually secularized during the 18th century, james Bryant Conant led the university through the Great Depression and World War II and began to reform the curriculum and liberalize admissions after the war. The undergraduate college became coeducational after its 1977 merger with Radcliffe College, Harvards $34.5 billion financial endowment is the largest of any academic institution. Harvard is a large, highly residential research university, the nominal cost of attendance is high, but the Universitys large endowment allows it to offer generous financial aid packages. Harvards alumni include eight U. S. presidents, several heads of state,62 living billionaires,359 Rhodes Scholars. To date, some 130 Nobel laureates,18 Fields Medalists, Harvard was formed in 1636 by vote of the Great and General Court of the Massachusetts Bay Colony. In 1638, it obtained British North Americas first known printing press, in 1639 it was named Harvard College after deceased clergyman John Harvard an alumnus of the University of Cambridge who had left the school £779 and his scholars library of some 400 volumes. The charter creating the Harvard Corporation was granted in 1650 and it offered a classic curriculum on the English university model—many leaders in the colony had attended the University of Cambridge—but conformed to the tenets of Puritanism. It was never affiliated with any denomination, but many of its earliest graduates went on to become clergymen in Congregational. The leading Boston divine Increase Mather served as president from 1685 to 1701, in 1708, John Leverett became the first president who was not also a clergyman, which marked a turning of the college toward intellectual independence from Puritanism. When the Hollis Professor of Divinity David Tappan died in 1803 and the president of Harvard Joseph Willard died a year later, in 1804, in 1846, the natural history lectures of Louis Agassiz were acclaimed both in New York and on the campus at Harvard College. Agassizs approach was distinctly idealist and posited Americans participation in the Divine Nature, agassizs perspective on science combined observation with intuition and the assumption that a person can grasp the divine plan in all phenomena. When it came to explaining life-forms, Agassiz resorted to matters of shape based on an archetype for his evidence. Charles W. Eliot, president 1869–1909, eliminated the position of Christianity from the curriculum while opening it to student self-direction. While Eliot was the most crucial figure in the secularization of American higher education, he was motivated not by a desire to secularize education, during the 20th century, Harvards international reputation grew as a burgeoning endowment and prominent professors expanded the universitys scope. Rapid enrollment growth continued as new schools were begun and the undergraduate College expanded. Radcliffe College, established in 1879 as sister school of Harvard College, Harvard became a founding member of the Association of American Universities in 1900. In the early 20th century, the student body was predominately old-stock, high-status Protestants, especially Episcopalians, Congregationalists, by the 1970s it was much more diversified
8.
Flamethrower
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A flamethrower is a mechanical incendiary device designed to project a long, controllable stream of fire. They were first used by the Greeks in the 1st Century AD, in modern times, they were used during World War I, and more widely in World War II. Some flamethrowers project a stream of ignited flammable liquid, some project a long gas flame, most military flamethrowers use liquids, but commercial flamethrowers tend to use high-pressure propane and natural gas, which is considered safer. They are used by the military and by people needing controlled burning capacity and they can be designed to be either carried by the operator or mounted on a vehicle. Modern flamethrowers were first used during the trench warfare conditions of World War I and they can be vehicle mounted, as on a tank, or man-portable. The man-portable flamethrower consists of two elements, a backpack and the gun, the backpack element usually consists of two or three cylinders. In a two-cylinder system, one cylinder holds compressed, inert propellant gas, a three-cylinder system often has two outer cylinders of flammable liquid and a central cylinder of propellant gas to maintain the balance of the soldier carrying it. The gas propels the liquid out of the cylinder through a flexible pipe. The igniter can be one of several systems, A simple type is an electrically-heated wire coil, another used a small pilot flame. The flamethrower is a potent weapon with great impact upon unprepared soldiers. This has led to calls for the weapon to be banned. It is primarily used against battlefield fortifications, bunkers, and other protected emplacements, typically, popular visual media depict the flamethrower as short-ranged and only effective for a few meters. Flamethrowers pose many risks to the operator, the first disadvantage was the weapons weight, which impairs the soldiers mobility. The weapon is limited to only a few seconds of time since it uses fuel very quickly, requiring the operator to be precise. The weapon was very visible on the battlefield, which caused operators to become immediately singled out as prominent targets, Flamethrower operators were rarely taken prisoner, especially when their target survived an attack by the weapon, captured flamethrower users were in some cases summarily executed. Finally, the effective range was short in comparison with that of other battlefield weapons of similar size. To be effective, flamethrower soldiers must approach their target, risking exposure to enemy fire, vehicular flamethrowers also have this problem, they may have considerably greater range than a man-portable flamethrower, but their range is still short compared with that of other infantry weapons. The risk of an operator being caught in the explosion of his weapon due to enemy hits on the tanks is exaggerated in Hollywood films
9.
Air raids on Japan
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Allied forces conducted many air raids on Japan during World War II, causing extensive destruction to the countrys cities and killing between 241,000 and 900,000 people. During the first years of the Pacific War these attacks were limited to the Doolittle Raid in April 1942, Strategic bombing raids began in June 1944 and continued until the end of the war in August 1945. Allied naval and land-based tactical air units also attacked Japan during 1945, the United States military air campaign waged against Japan began in earnest in mid-1944 and intensified during the wars last months. While plans for attacks on Japan had been prepared prior to the Pacific War, from June 1944 until January 1945, B-29s stationed in India staged through bases in China to make a series of raids on Japan, but this effort proved unsuccessful. The strategic bombing campaign was expanded from November 1944 when bases in the Mariana Islands became available as a result of the Mariana Islands Campaign. Aircraft flying from Allied aircraft carriers and the Ryukyu Islands also frequently struck targets in Japan during 1945 in preparation for the invasion of Japan scheduled for October 1945. During early August 1945, the cities of Hiroshima and Nagasaki were struck, Japans military and civil defenses were unable to stop the Allied attacks. Fuel shortages, inadequate training, and a lack of coordination between units also constrained the effectiveness of the fighter force. Despite the vulnerability of Japanese cities to firebombing attacks, the firefighting services lacked training and equipment, as a result, the B-29s were able to inflict severe damage on urban areas while suffering few losses. The Allied bombing campaign was one of the factors which influenced the Japanese governments decision to surrender in mid-August 1945. However, there has been a debate over the morality of the attacks on Japanese cities. The most commonly cited estimate of Japanese casualties from the raids is 333,000 killed and 473,000 wounded, there are a number of other estimates of total fatalities, however, which range from 241,000 to 900,000. In addition to the loss of civilian life, the raids contributed to a large decline in industrial production. The United States Army Air Corps began developing plans for an air campaign against Japan during 1940. The first American Volunteer Group began operations as part of the Chinese Air Force in late 1941 using P-40 Warhawk fighter aircraft, a second American Volunteer Group was also formed in late 1941 to attack Japan from bases in China using Hudson and A-20 Havoc medium bombers. The attack on Pearl Harbor on 7 December 1941 led to hostilities between the US and Japan and ended the need for covert operations, however, and this unit did not become active. The small number of Second Air Volunteer Group personnel who were dispatched from the United States in November 1941 were diverted to Australia upon the outbreak of war. Before the outbreak of war, the USAAF had planned to bomb Japan from Wake Island, Guam, the Philippines and coastal areas in China
10.
Close air support
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The requirement for detailed integration because of proximity, fires or movement is the determining factor. CAS may need to be conducted during shaping operations with Special Operations Forces, if the mission requires detailed integration with the fire, the term battlefield air interdiction is not currently used in U. S. joint doctrine. Close air support requires excellent coordination with ground forces, in advanced modern militaries, this coordination is typically handled by specialists such as Joint Fires Observers s, Joint Terminal Attack Controllers s, and Forward Air Controllers s. The use of aircraft in the air support of ground forces dates back to World War I. By that point, the startling and demoralizing effect that attack from the air could have on the troops in the trenches had been made clear, at the Battle of the Somme,18 British armed reconnaissance planes strafed the enemy trenches after conducting surveillance operations. The success of this improvised assault spurred innovation on both sides, in 1917, following the Second Battle of the Aisne the British debuted the first ground-attack aircraft, a modified F. E 2b fighter carrying 20-lb bombs and mounted machine-guns. After exhausting their ammunition the planes returned to base for refuelling and rearming, other modified planes used in this role were the Airco DH.5 and Sopwith Camel—the latter was particularly successful in this role. Aircraft support was first integrated into a plan on a large scale at the 1917 Battle of Cambrai. British doctrine at the time came to two forms of air support, trench strafing, and ground strafing —attacking tactical ground targets away from the land battle. As well as strafing with machine-guns, the planes were modified with bomb racks, the Germans were also quick to adopt this new form of warfare and were able to deploy aircraft in a similar capacity at Cambrai. While the British used single-seater planes, the Germans preferred the use of heavier two-seaters with a machine gunner in the aft cockpit. The Germans adopted the powerful Hannover CL. II and built the first purpose built ground attack aircraft, during the 1918 Spring Offensive the Germans employed 30 squadrons, or Schlasta, of ground attack fighters and were able to achieve some initial tactical success. The British later deployed the Sopwith Salamander as a ground attack aircraft. It was during the Sinai and Palestine Campaign of 1918 that Close Air Support was first proven to be an important factor in ultimate victory, combined with a ground assault led by General Edmund Allenby, three Turkish armies soon collapsed into a full rout. In the words of the squadrons official report, No 1 Squadron made six heavy raids during the day. The panic and slaughter beggared description, the close air support doctrine was further developed in the interwar period. Most theorists advocated the adaptation of fighters or light bombers into the role, during this period, airpower advocates crystallized their views on the role of air-power in warfare. Aviators and ground officers developed largely opposing views on the importance of CAS, the inter-war period saw the use of CAS in a number of conflicts, including the Russo-Polish War, the Spanish Civil War, colonial wars in the Middle East and the Gran Chaco War
11.
World War I
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World War I, also known as the First World War, the Great War, or the War to End All Wars, was a global war originating in Europe that lasted from 28 July 1914 to 11 November 1918. More than 70 million military personnel, including 60 million Europeans, were mobilised in one of the largest wars in history and it was one of the deadliest conflicts in history, and paved the way for major political changes, including revolutions in many of the nations involved. The war drew in all the worlds great powers, assembled in two opposing alliances, the Allies versus the Central Powers of Germany and Austria-Hungary. These alliances were reorganised and expanded as more nations entered the war, Italy, Japan, the trigger for the war was the assassination of Archduke Franz Ferdinand of Austria, heir to the throne of Austria-Hungary, by Yugoslav nationalist Gavrilo Princip in Sarajevo on 28 June 1914. This set off a crisis when Austria-Hungary delivered an ultimatum to the Kingdom of Serbia. Within weeks, the powers were at war and the conflict soon spread around the world. On 25 July Russia began mobilisation and on 28 July, the Austro-Hungarians declared war on Serbia, Germany presented an ultimatum to Russia to demobilise, and when this was refused, declared war on Russia on 1 August. Germany then invaded neutral Belgium and Luxembourg before moving towards France, after the German march on Paris was halted, what became known as the Western Front settled into a battle of attrition, with a trench line that changed little until 1917. On the Eastern Front, the Russian army was successful against the Austro-Hungarians, in November 1914, the Ottoman Empire joined the Central Powers, opening fronts in the Caucasus, Mesopotamia and the Sinai. In 1915, Italy joined the Allies and Bulgaria joined the Central Powers, Romania joined the Allies in 1916, after a stunning German offensive along the Western Front in the spring of 1918, the Allies rallied and drove back the Germans in a series of successful offensives. By the end of the war or soon after, the German Empire, Russian Empire, Austro-Hungarian Empire, national borders were redrawn, with several independent nations restored or created, and Germanys colonies were parceled out among the victors. During the Paris Peace Conference of 1919, the Big Four imposed their terms in a series of treaties, the League of Nations was formed with the aim of preventing any repetition of such a conflict. This effort failed, and economic depression, renewed nationalism, weakened successor states, and feelings of humiliation eventually contributed to World War II. From the time of its start until the approach of World War II, at the time, it was also sometimes called the war to end war or the war to end all wars due to its then-unparalleled scale and devastation. In Canada, Macleans magazine in October 1914 wrote, Some wars name themselves, during the interwar period, the war was most often called the World War and the Great War in English-speaking countries. Will become the first world war in the sense of the word. These began in 1815, with the Holy Alliance between Prussia, Russia, and Austria, when Germany was united in 1871, Prussia became part of the new German nation. Soon after, in October 1873, German Chancellor Otto von Bismarck negotiated the League of the Three Emperors between the monarchs of Austria-Hungary, Russia and Germany
12.
Urban warfare
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Urban warfare is combat conducted in urban areas such as towns and cities. Urban combat is very different from combat in the open at both the operational and tactical level, complicating factors in urban warfare include the presence of civilians and the complexity of the urban terrain. Fighting in urban areas negates the advantages that one side may have over the other in armour, heavy artillery, some civilians may be difficult to distinguish from combatants such as armed militias and gangs, and particularly individuals who are simply trying to protect their homes from attackers. The United States Armed Forces term for urban warfare is UO, the previously used U. S. military term MOUT, an abbreviation for military operations in urban terrain, has been replaced by UO, although the term MOUT Site is still in use. The British armed forces terms are OBUA, FIBUA, or sometimes FISH, or FISH, israel Defense Forces calls urban warfare לשב, a Hebrew acronym for warfare on urban terrain. LASHAB in the IDF includes large-scale tactics, CQB training for fighting forces, the IDF has a special large and advanced facility for training soldiers and units in urban warfare. Urban military operations in World War II often relied on large quantities of artillery bombardment, in some particularly vicious urban warfare operations such as Stalingrad and Warsaw, all weapons were used irrespective of their consequences. However, when liberating occupied territory some restraint was often applied, Military forces are bound by the laws of war governing military necessity to the amount of force which can be applied when attacking an area where there are known to be civilians. Until the 1970s, this was covered by the 1907 Hague Convention IV – The Laws, sometimes distinction and proportionality, as in the case of the Canadians in Ortona, causes the attacking force to restrain from using all the force they could when attacking a city. In other cases, such as the Battle of Stalingrad and the Battle of Berlin, when Russian forces attacked Grozny in 1999, large amounts of artillery fire were used. Fighting in an environment can offer some advantages to a weaker defending force or to guerrilla fighters through ambush-induced attrition losses. The attacking army must account for three dimensions more often, and consequently expend greater amounts of manpower in order to secure a myriad of structures, and mountains of rubble. Ferroconcrete structures will be ruined by heavy bombardment, but it is difficult to demolish such a building totally when it is well defended. The characteristics of a city include tall buildings, narrow alleys, sewage tunnels. Defenders may have the advantage of detailed knowledge of the area, right down to the layout inside of buildings. The buildings can provide excellent sniping posts while alleys and rubble-filled streets are ideal for planting booby traps, defenders can move from one part of the city to another undetected using underground tunnels and spring ambushes. Meanwhile, the attackers tend to more exposed than the defender as they must use the open streets more often, unfamiliar with the defenders secret. During a house to search the attacker is often also exposed on the streets
