Task Force Leatherneck or MEB-Afghanistan was a Marine Air-Ground Task Force that operated in Helmand Province, Afghanistan. The name was originally given to the 2nd Marine Expeditionary Brigade during its 2009-10 operations for OPERATION ENDURING FREEDOM. On July 3, 2010, it was renamed as Regional Command Southwest, RC(SW)|, and in January of 2015 it was renamed Train Advise Assist Command - Southwest (TAAC-SW) under the new NATO mission RESOLUTE SUPPORT. It is also the name used by the 1st Marine Division and 2nd Marine Division during their deployments to Afghanistan. Task Force Leatherneck was commanded by Brigadier General Lawrence D. Nicholson with the command element at Camp Leatherneck. The task force took over the battlespace from Special Purpose MAGTF-Afghanistan on May 29, 2009. In July 2009, Task Force Leatherneck participated in Operation Strike of the Sword, the largest Marine Corps operation since the Battle of Fallujah, and then in February 2010 an even larger battle, the largest of the Afghan Campaign, Operation Moshtarak.

Operation Strike of the Sword or Operation Khanjar was a US-led offensive in Helmand province in southern Afghanistan. About 4,000 Marines from the 2nd Marine Expeditionary Brigade as well as 650 Afghan troops were involved, supported by NATO planes. The operation began when units moved into the Helmand River valley in the early hours of July 2, 2009. This operation was the largest Marine offensive since the Battle of Fallujah in 2004. The operation was also the biggest offensive airlift by the Marines since the Vietnam War.