He was criticising Trump's Syria withdrawal threats back in February
https://www.pbs.org/newshour/show/february-15-2019-pbs-newshour-full-episode

here is his major foreign policy speech
JUNE 11, 2019
Pete Buttigieg on U.S. Foreign Policy
South Bend, Indiana, Mayor Pete Buttigieg, a 2020 presidential candidate, gave a speech on U.S. foreign policy at Indiana University in Bloomington.
Pete Buttigieg just gave his first foreign policy speech. He offered 5 clear proposals.
Buttigieg outlined what hed do about climate change, Israel, Iran, and war.
https://www.vox.com/policy-and-politics/2019/6/11/18661329/pete-buttigieg-foreign-policy-speech-indiana-university
In a high-profile address on Tuesday at Indiana University, the South Bend mayor used the opportunity to lay out his worldview, hewing closely to progressive tentpoles like combating climate change, challenging authoritarianism, and renewing Americas economy. That put him in the same company as Sens. Elizabeth Warren (D-MA) and Bernie Sanders (I-VT), who have released likeminded visions.
What separated Buttigieg from that crowd, though, is that he put some meat on the conceptual progressive skeleton. Specifically, he said he would:
Repeal and replace the 2001 congressional authorization that the US military still uses to this day to fight terrorism and engage in foreign wars around the world
Recommit the US to the Iran nuclear deal
Withhold some US taxpayer money from Israel if it annexes parts of the West Bank
Rejoin the Paris climate accord
Increase investment in renewable technologies to reverse environmental degradation
Not only must America do this in order to prosper, Buttigieg told the friendly crowd, but the world also needs America to do these things.
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