[401] One week after his announcement, Trump said he would not approve any extension of the American deployment in Syria.[402]
In October 2019, after Trump spoke to Turkish president Recep Tayyip Erdoğan, U.S. troops in northern Syria were withdrawn from the area and Turkey invaded northern Syria, attacking and displacing American-allied Kurds in the area.[403] Later that month, the U.S. House of Representatives, in a rare bipartisan vote of 354 to 60, condemned Trump's withdrawal of U.S. troops from Syria, for "abandoning U.S. allies, undermining the struggle against ISIS, and spurring a humanitarian catastrophe".[404][405]

Iran
After an Iranian missile test on January 29, 2017, and Houthi attacks on Saudi warships, the Trump administration sanctioned 12 companies and 13 individuals suspected of being involved in Iran's missile program.[406] In May 2018, Trump withdrew the United States from the Joint Comprehensive Plan of Action (JCPOA), the 2015 agreement between Iran, the U.S., and five other countries that lifted most economic sanctions against Iran in return for Iran agreeing to restrictions on its nuclear program.[407][408] Analysts determined Iran moved closer to developing a nuclear weapon since the withdrawal.