In just over a week, the internal White House debate over Syria has been flipped on its head. Last week, the president was publicly vowing to pull U.S. troops out of Syria at the same moment administration officials were vowing they would stay in the country. During a National Security Council meeting, Defense Secretary James Mattis reportedly convinced a skeptical Trump that the military needed more time to finish the job of mopping up what’s left of ISIS. Trump agreed, as long as it would take “months, not years,” but said preparations to pull troops out should begin.

Now, after last weekend’s chemical attack in Douma and Trump’s series of tweets threatening action against “Animal Assad,” the president is reportedly pushing for what would be a major new level of U.S. military force in Syria, and Mattis is the one wary of escalation.

According to the Wall Street Journal, Trump has “privately pushed for a strong response that would try to cripple Syria’s ability to carry out further chemical-weapons attacks” and said that the U.S. must take much more forceful action than it did when it launched 59 tomahawk missiles in response to a chemical attack last year. Trump wants action that will punish Assad’s sponsors—Iran and Russia—in addition to the regime. Mattis, meanwhile, is advocating a more narrowly tailored response, noting the risk that new strikes “could inadvertently kill Russians working alongside Syrian forces.” Mattis has also said the U.S. is still gathering evidence on whether Assad was behind the chemical attack, contradicting both the president’s tweets and U.N. Ambassador Nikki Haley, who has said the U.S. already has “enough proof” to act. One Department of Defense official told the New York Times that Mattis’ more cautious stance is an “acknowledgment of a lesson from the Iraq war about what can go wrong after a military assault without a plan.” According to Just Security’s Kate Brannen, new national security adviser John Bolton, who started on Monday and was a loud advocate for the Iraq war, is siding with Trump.

Obviously, the terms of last week’s Syria debate and this week’s are not the same—an enduring troop presence is different from a massive airstrike, and a chemical attack is different from other forms of warfare. But it’s still jarring to see how fast the president will drop his usual skepticism about military intervention in the Middle East, prompted perhaps by visceral disgust—the images of the most recent Douma attack were certainly heart-wrenching, but also not out of character for Assad’s crimes during this long and brutal war—or the chance to distinguish himself from Barack Obama.

There’s an arguable case to be made that limited strikes might be worth it if only to uphold the international norm against the use of chemical weapons, even if such strikes are unlikely to shift the course of the war and could even prolong it. The legal, moral, and strategic case for the type of wider, riskier intervention that Trump seems to be favoring, though, is much weaker.

While this debate goes on, Trump’s threats already appear to be having an impact on the ground in Syria, reports the Telegraph’s Raf Sanchez. The good news is that there have been no regime airstrikes since last Tuesday. The bad news is that Syrian regime forces appear to be moving aircraft to Russian bases in Syria, meaning that it will be much harder for any U.S. military action to achieve the results Trump wants without the dangerous escalation that Mattis fears.