Sen. Lindsey Graham (R-SC) on Wednesday denounced President Trump’s decision to withdraw troops out of northeastern Syria, abandoning our Kurdish allies as they’re attacked by Turkish forces. “I hope President Trump is right in his belief that Turkeys invasion of Syria is of no concern to us, abandoning the Kurds won’t come back to haunt us, ISIS won’t reemerge, and Iran will not fill the vacuum created by this decision,” Graham wrote in a series of tweets. “However, I firmly believe that if President Trump continues to make such statements this will be a disaster worse than President Obama’s decision to leave Iraq.”

Graham has been a dependable supporter of the president, but has disagreed with him over Middle East foreign policy. The senator also cautioned that Trump’s rhetoric following the decision “will undercut Vice President Pence and Sec. Pompeo’s ability to end the conflict.” “I worry we will not have allies in the future against radical Islam, ISIS will reemerge, & Iran’s rise in Syria will become a nightmare for Israel,” Graham wrote. “I fear this is a complete and utter national security disaster in the making and I hope President Trump will adjust his thinking.”