Ever since former defense secretary Jim Mattis resigned over President Trump’s announced withdrawal from Syria, he has declined to directly criticize or even address Trump’s decision-making as president.

Brett McGurk is showing no such deference.

McGurk, who served as Trump’s envoy for the fight against the Islamic State, lit into Trump early Monday over the White House’s announcement that it is essentially handing northern Syria over to Turkey — a decision many feel could lead to Turkey slaughtering the United States’ Kurdish allies in the region.

McGurk took the occasion to not just criticize Trump’s immediate decision; he used it to cast a picture of a president who makes rash life-or-death decisions without the appropriate amount of thought. Essentially, he confirmed Trump critics’ worries about how the president prosecutes U.S. involvement in wars and conducts foreign policy.

“Donald Trump is not a Commander-in-Chief,” said McGurk, who resigned along with Mattis over Trump’s initial (but later aborted) plan for a full Syria withdrawal. “He makes impulsive decisions with no knowledge or deliberation. He sends military personnel into harm’s way with no backing. He blusters and then leaves our allies exposed when adversaries call his bluff or he confronts a hard phone call.”

McGurk also suggested the people around Trump have no idea what’s going on. He noted that the White House’s statement says the United States will not hold Islamic State fighters and how the decision will save U.S. taxpayer money, but the United States isn’t actually holding those fighters.

U.S. officials have long said these fighters are being held by the Syrian Democratic Forces (SDF), a Kurdish-led military force, with U.S. assistance. Despite this, Trump has said before that the United States is “holding thousands of ISIS fighters right now.”

These statements often seem as though they were dictated by Trump without the normal care and fact-checking that would usually be involved in such high-stakes foreign policy announcements. McGurk seems to indicate that’s exactly what’s going on.

The decision notably comes after a phone call Trump had with Turkish President Recep Tayyip Erdogan. Trump will often make major decisions after such phone calls; his December announcement that the United States would completely withdraw from Syria also came immediately after a call with Erdogan. Trump later decided to leave some forces in the country.

Trump apparently made the latest decision without consulting much of anyone domestically, including Sen. Lindsey O. Graham (R-S.C.), who tweeted Monday morning a statement that “I don’t know all the details." But, he added, “If press reports are accurate this is a disaster in the making.” Ditto Sen. Marco Rubio (R-Fla.). Reports indicate the Pentagon didn’t know either — which has been par for the course for many of these kinds of decisions.

McGurk then proceeded to make the argument that many others were making — about how this could be calamitous for the Kurds in the region. The Kurds have been key U.S. allies for years, including teaming up in Syria, and the United States has assured it would protect them in an unwieldy conflict with many competing interests.

McGurk noted that the U.S. European Command tweeted just this weekend about the “security mechanism” it put in place for the SDF.

McGurk then concluded by calling Trump a “minimalist president” who undertakes “no process to assess fact, develop options, or prepare contingencies.” He called Trump’s decision a “gift to Russia, Iran, and ISIS.”

Trump supporters will probably dismiss this as sour grapes by a former Trump adviser whose advice Trump didn’t heed. They’ll note he was a holdover from the Obama administration, although Trump kept him on for almost two full years after that.

But the statement released late Sunday followed a pattern in which these massive decisions appear to be made on the fly, without regard for the facts on the ground, because a foreign leader said the right things to Trump on a phone call. And McGurk, who has plenty of experience on this stuff, says that appearance doesn’t deceive.