What is Jim Mattis thinking right about now?

President Trump’s defense secretary, widely considered to be one of the dwindling number of reality-based officials keeping the president from dangerous and permanent derailment, resigned on Dec. 20. Although his resignation letter made no specific mention of Syria, Mattis chose to hand it in the day after Trump surprised advisers and nearly everyone by announcing that the U.S. was pulling its small military force from Syria. The decision shook many in Congress, including senior Republicans. But Vladimir Putin thought it was a great idea.

Mattis is all about being very clear who your friends and enemies are, and in each case treating them as such. The president, he said, deserved a secretary of defense who better reflected his values.

So what happened after he resigned? Instead of allowing Mattis to serve until the end of February, the date he had offered to leave the Pentagon, Trump moved his departure up to Jan. 1 and said he had “essentially fired” Mattis. That’s predictable enough, since Mattis made Trump look bad. He already was on shaky ground, and it had only seemed a matter of time before Mattis joined the rest of the “adults” in the administration on the outside looking in.

But also note what’s happened to Trump’s dramatic shift in Syria policy. On a visit Monday to Israel, National Security Adviser John Bolton said the 2,000-member U.S. force wouldn’t leave Syria until several conditions are met, including total defeat of the Islamic State and security for America’s Syrian Kurdish allies. Bolton refused to even talk about a timetable for withdrawal.

Of course, this being the Trump administration, that might change tomorrow. It probably will change again sometime during Trump’s presidency. But as of now, we appear to be back where we were the day before Trump made his announcement — except that the Defense Department now is being led by a guy whose last stop before the Pentagon was a senior vice president of Boeing, rather than a former Marine general who commanded troops in Afghanistan and both Iraq wars.

Judging from how he has handled his many other personnel issues, you have to think Trump feels okay about this one. In any case, no one is talking about it much — the discussion in Washington now is all about the government shutdown and border wall. His new acting defense secretary can sit at the next Cabinet meeting next to an acting chief of staff, acting secretary of the interior, acting head of the environmental protection agency and acting attorney general. The U.S. doesn’t have an ambassador to the U.N. right now, either — which on balance might be a good thing, since Trump’s nominee is a former Fox News host.

Mattis almost certainly knew this day was coming; just not exactly when or what issue would precipitate his departure. Despite a sense of duty honed in four decades in the Marine Corps, it has to feel good to stop hitting your head against the wall. And perhaps he created enough of a stir on his way out that he helped force the reversal we appear to be witnessing. It’s not clear what happened. But Trump enemy-turned-friend Lindsay Graham, for example, declared such an immediate withdrawal from Syria “against sound military advice” to be “a stain on the honor of the United States,” that would make the country less secure. Israeli officials expressed concerns that departure of U.S. troops would make it easier for Iran and its ally Hezbollah to build up forces on the Israeli border. Perhaps that gave Bolton and Secretary of State Mike Pompeo an opening to slow Trump down.

To be clear, this is less about the policy than about how it is or is not implemented. Keeping a couple of thousand troops in a dangerous place like Syria fulfills a couple of U.S. goals — pressuring Iran, keeping up the fight against remnants of the Islamic State, keeping faith with an ally, countering Russia. But it’s not much of a long-term plan. It’s what you do when you feel like you need to do something, but all the options are lousy. President Obama discovered the same thing in Syria. In a nutshell, that’s why we’re still in Afghanistan.

Trump may basically be right about Syria — just going about it in the worst possible way. As usual. The method may be as worrisome as the policy itself. If Trump insists on getting out, it should be accomplished in a clear and carefully scripted manner. America’s friends must know what to expect; rivals must be clear about the consequences should they try to take advantage.

Mattis may no longer be at the Pentagon, but he has an important role in this debate. He certainly would argue against a precipitous withdrawal. Perhaps more important, he should be answer questions in public about his decision to resign, and about his overall relationship with Trump. He should testify openly if asked by House committees. He should do interviews, write articles, perhaps go on a speaking tour. He might prefer not to, but that’s where duty should take him now.