International Security Assistance Force Joint Command
Army Lt. Gen. Joseph Anderson, commander of International Security Assistance Force Joint Command, and Royal Army Maj. Gen. Richard Nugee, ISAF chief of staff, lower the ISAF Joint Command colors at Kabul International Airport, Afghanistan, during a casing ceremony marking the end of the ISAF Joint Command mission. Department of Defense/Staff Sgt. Perry Aston

The U.S. and NATO closed their International Security Assistance Force Joint Command's headquarters at Kabul International Airport Monday. The joint combat mission in Afghanistan will end on Dec. 31 but 12,000 troops will remain in the country. Military bases and command centers in Afghanistan have been given over to the Afghan Armed Forces.

"As the Afghan National Security Forces have become increasingly capable, we shift our focus from combat operations to building [Afghan] systems and processes to ensure long-term sustainability," Army Gen. John F. Campbell, ISAF commander, said in a statement.

Regional Command East
Regional Command East was deactivated on Nov. 4, 2014. Department of Defense/Master Sgt. Kap Kim

In November, Regional Command East was deactivated. RC-East, spanning 14 provinces across Afghanistan's eastern border with Pakistan, was described by Vice President Joe Biden as the "most dangerous place in the world" during his 2012 vice presidential debate with Rep. Paul Ryan of Wisconsin.

"The Afghan Security Forces are more capable of securing their people, their elections in 2014 and their future," Maj. Gen. James C. McConville, commanding general, 101st Airborne Division (Air Assault), said of RC-East's role in 2013. "They are better equipped and better prepared to secure Afghanistan, protect its territories and people and enforce the rule of law. With ongoing support from NATO, ISAF and the broader international community, Afghanistan has successfully recruited, trained and organized large, capable and integrated forces that the Afghan people have grown to embrace as the pride of their nation."

Camp Leatherneck
Camp Leatherneck was handed over to Afghanistan in October. Department of Defense

In October, the U.S. and U.K handed over Camp Leatherneck and Camp Bastion to the Afghan military. Camp Bastion served as the U.K. headquarters in the country and in 2012 was attacked by the Taliban. At the time, Prince Harry was stationed at the camp and the target of the Taliban raid but was taken to a secure location, GQ reported.

Kabul Military Training Center
A soldier in Afghan national engineer brigade in a construction exercise at the Kabul Military Training Center. Department of Defense

While American forces have recently served as support for the Afghan military, President Barack Obama expanded the military's role in the country, CBS News reported. The U.S. can provide air support for combat missions and allows for the targeting of the Taliban in addition to al Qaeda.

Afghan National Army
Afghan National Army soldiers taking part in a training exercise. Reuters