As CENTCOM commander, McKenzie oversaw the successful high-profile special forces raid in Syria to kill or capture then-Islamic State leader Abu Bakr al-Baghdadi in October 2019, and the 2020–2021 withdrawals and reductions of U.S. troops from Iraq. He also oversaw the Afghanistan withdrawal. McKenzie replaced General Austin "Scott" Miller as leader of U.S. and NATO forces in Afghanistan upon the latter's resignation on July 12, 2021, with Miller's departure perceived by some as "the symbolic end of the U.S. military mission in Afghanistan."