"This decision is a disaster," said Sen. Lindsey Graham (R-SC), who spared no words for the President in a Senate floor speech on Thursday night.
"The decision today by the President, and I think it was his alone, I think is disastrous to our own national security," Graham added.
"We will remember this day as a major blunder," said Sen. Marco Rubio (R-FL), who echoed Graham's searing criticism, all but accusing the President of selling out Kurdish fighters in order to please leaders in Turkey.
"I honestly believe that this is a catastrophic decision for America's national security interests," Rubio added.
"Why are we doing this?" Rubio asked on the Senate floor, as he noted the excited reaction of the Russian Embassy in the United States.
Meanwhile, House Democratic Leader Nancy Pelosi raised the specter of the President acting in a way which would benefit Turkey - whose authoritarian regime has been favored by Mr. Trump - and at one time was employing the President's former National Security Adviser, Michael Flynn.
"All Americans should be concerned that this hasty announcement was made on the day after sentencing in criminal proceedings began against the President’s former National Security Advisor Michael Flynn, who admitted that he was a registered foreign agent for a country with clear interests in the Syrian conflict," Pelosi said.