Michael McFaul told Newsweek the president will likely interpret his Senate success as proof "he knows best."
Former Secretary of State John Kerry told an Iowa crowd Monday that Donald Trump "wouldn't qualify for security clearance" had he not become president.
"Where's the Republican leadership in Congress to say 'no'?" Senator Ben Cardin asked in an interview with Fox News Sunday.
"That's really dangerous," Republican Representative Adam Kinzinger warned.
The president told supporters in Hershey that the country was "laughed at" four years ago under the Obama administration.
The president has said that a deal to end his long-running trade war with Beijing is close at hand, but has Trump succeeded in his goal of bringing China to heel?
Former U.S. Navy intelligence and counter-terrorism specialist Malcolm Nance suggested, "Putin leads Donald Trump around on a leash."
Molly Montgomery said the current State Department is "far from having swagger" and is instead "limping along at the moment."
The dictator suggested Trump's transactional foreign policy is illustrative of America's global approach.
Trump said this weekend he would like to get U.S. companies into eastern Syria to "properly" exploit the oil fields there.
The president said Wednesday that the U.S. would now "let someone else fight over this long bloodstained sand."
Michael McFaul said President Donald Trump has "personalized" and "privatized" U.S. foreign policy at great cost to the country.
The president has come under fire from Republican lawmakers over his Syria troop withdrawal, allowing Turkey's invasion of Kurdish areas.
"We're in trouble," Steve Schmidt said in a Monday interview. "You see America in retreat, literally."
New Jersey Democratic Senator Bob Menendez said it's no coincidence that Russia continues getting foreign policy victories over the Trump administration.
Buttigieg rejected any proposal to "completely withdraw" troops from the Middle East, and said President Trump's erratic foreign policy is affecting Americans' safety.
Mick Mulvaney told reporters yesterday that the Trump administration uses quid pro quo "all the time with foreign policy." He later walked back the comments.
"I have news for everybody: Get over it," Mulvaney told reporters on Thursday.
"There is a project to eradicate Kurds," SDF spokesman Mustafa Bali said. "Therefore, our first duty is the protection of our people, border and soil."
Just hours after Trump threatened to "obliterate" Turkey's economy, he described the country as one of America's biggest and most honest trading partners
Jason Kander alleged that Trump prioritizes Russian interests over U.S. ones, which he said is "reason enough to impeach."
"Trump not saying much (because) he doesn't know much," said George Conway, the husband of counselor to the president Kellyanne Conway.
Former White House National Security Adviser John Bolton was among several alarmed administration officials who urged President Trump to release the nearly $400 million in funds to Ukraine, officials said.
Sergey Shoigu said Russia will focus on weapons to level the playing field against overwhelming U.S. force.
The former secretary of state called on the White House to release the transcript of the suspect phone call, calling it the only way to discover the truth.
Actions such as withdrawing from the Iran nuclear deal have resulted in a Middle East foreign policy by Trump as something that's "essentially become a Saudi wish list," Ben Rhodes said.
Trump announced Bolton's departure on Twitter on Tuesday, saying he had disagreed with "many" of his adviser's suggestions.
Ukraine's new leader is meeting with key European leaders this week.
The president's foreign policy is "totally at odds with what the U.S. intelligence community believes," Jeremy Bash argued.
"I worry that the bottom line of that kind of an approach is we have an administration that looks a lot more like Barack Obama than Ronald Reagan," former Vice President Dick Cheney told Mike Pence.