President-elect Donald Trump has chosen Sen. Marco Rubio for secretary of state and Rep. Mike Waltz for national security adviser, both of whom share Trump's hard-line stance on China and Iran. Rubio and Waltz are mainstream conservatives with foreign policy experience who have previously differed with Trump on Russia, NATO, and other issues. Rubio, a senior member of the Senate Intelligence Committee and Foreign Relations Committee, has been instrumental in securing the U.S. position in NATO. Both Rubio and Waltz have altered their positions to align more closely with Trump's criticism of the Biden administration's backing of Ukraine. China and Iran may be wary of Trump's picks.