Resolute Support Mission

The Resolute Support Mission (RSM) was a NATO-led operation in Afghanistan that began on 1 January 2015, succeeding the combat-focused International Security Assistance Force (ISAF). Unlike ISAF, RSM was explicitly a non-combat "train, advise, and assist" mission directed at the Afghan National Defense and Security Forces (ANDSF) and Afghan ministries.

Its legal basis was the Status of Forces Agreement and the Bilateral Security Agreement signed between NATO/the United States and the Afghan government in September 2014, together with UN Security Council endorsement. The mission operated under a "hub and spoke" model, with a central headquarters in Kabul and Train, Advise, Assist Commands (TAACs) in the north (Mazar-e-Sharif), south (Kandahar), east (Laghman/Bagram), west (Herat), and capital region.

RSM included troop contributions from all NATO members plus partner states such as Australia, Georgia, Sweden, and Finland, peaking at roughly 16,000 personnel in 2018 before declining. The United States provided the largest contingent and ran a parallel counter-terrorism mission, Operation Freedom's Sentinel.

Key tasks included:

• Advising Afghan ministries of defense and interior at the institutional level
• Training the Afghan Air Force and special operations units
• Supporting force generation, payroll, and logistics systems
• Assisting counter-narcotics and rule-of-law efforts

Following the February 2020 Doha Agreement between the United States and the Taliban, NATO began conditions-based drawdown. President Biden's April 2021 announcement set a full withdrawal deadline, and RSM formally concluded in early September 2021 as the Taliban retook Kabul on 15 August 2021. The mission's collapse alongside the ANDSF prompted extensive after-action reviews within NATO, the U.S. Congress, and SIGAR (Special Inspector General for Afghanistan Reconstruction) regarding the sustainability of externally built security forces.