Operation Moshtarak, also known as the Battle of Marjah, was an International Security Assistance Force (ISAF) pacification offensive in the town of Marjah, Helmand Province, Afghanistan. It involved a combined total of 15,000 Afghan, American, British, Canadian, Danish, and Estonian troops, constituting the largest joint operation of the War in Afghanistan up to that point. The purpose of the operation was to remove the Taliban from Marja, thus eliminating the last Taliban stronghold in central Helmand Province. The main target of the offensive was the town of Marjah, which had been controlled for years by the Taliban as well as drug traffickers.

Marjah is an agricultural town in southern Afghanistan. It has been reported to have a population between 80,000 and 125,000, but some sources argue that its population is much smaller and is spread across 80 to 125 km2, an area larger than Cleveland or Washington, D.C. Another source described Marjah as "a cluster of villages" and "a community of 60,000 persons". The town sits in Nad Ali District of Helmand Province, southwest of the provincial capital Lashkar Gah.