O'Rourke supported the Iran nuclear deal regarding Iran's development of weapons of mass destruction. In August 2017, O'Rourke criticized Trump's hard-line stance towards North Korea, saying that "We must not allow this president to sleepwalk this country, or tweet this country, into war with North Korea." In March 2019, O'Rourke called for ending the U.S.–led Iraq War and War in Afghanistan. O'Rourke opposed the U.S. involvement in the Syrian Civil War and providing arms to the rebel fighters in Syria. He also criticized the NATO-led military intervention in Libya a "factor in the destabilization of the Middle East and the rise of ISIS." O'Rourke supported legislation to curtail NSA's broad and unwarranted surveillance of U.S. and foreign citizens.