He’ll speak live from Fort Myer at 9 pm ET. One never knows what the president will do until he opens his mouth, but every indication is that he’s siding with Mattis and McMaster and ordering a surge. A small one:

President Trump has signed off on sending an additional 4,000 troops to Afghanistan, ahead of his address to the nation Monday night, Fox News has learned…

“I think he is going to give [his generals] a chance to prove what they want and their strategy,” former Trump deputy campaign manager David Bossie told “Fox & Friends,” noting that Trump can adjust the plan in the future…

The Pentagon was awaiting a final announcement by Trump on a proposal to send in nearly 4,000 more U.S. troops, on top of the 8,400 in the country. The added forces would increase training and advising of the Afghan forces and bolster counterterrorism operations against the Taliban and the Islamic State affiliate trying to gain a foothold in the country.

We’re a long way from citizen Trump expressing opinions like this…

…but maybe not as long as it seems. One worry with a mercurial president is that he won’t stick with a strategy that conflicts with his own instincts if it doesn’t pay off quickly, or even that he’ll change his mind about the order he intends to give before announcing it this evening. White House aides are sweating:

[N]o U.S. official wants to jinx the strategy announcement by leaking what Trump approved at Camp David last Friday, lest the president change his mind in a fit of pique over someone stealing his thunder, one U.S. official joked…

“They won’t give anyone an advance preview,” said one frustrated senior defense official…

A senior administration official strongly contested the notion that Trump might change his mind, saying he’d been growing more comfortable with the way ahead, as his advisors worked through his questions like ‘what would be different than before’?

The alleged virtue of the new strategy is that it comes without a withdrawal deadline, which supposedly will erode the Taliban’s morale and force them to sue for peace. If the U.S. presence is indefinite then the Taliban has no incentive to keep fighting and local powers like Pakistan, Iran, and Russia have no incentive to keep propping them up. In reality, an enemy that’s fought for 16 years will go on fighting for a few more knowing that America is tired of this war and aimless in its goals, reduced to training and retraining an Afghan national force that’ll seemingly never be ready to stand on its own against the Taliban and perhaps isn’t even inclined to. Trump is ordering the surge because he doesn’t want to be viewed as the president who gave up on Afghanistan, which is understandable, but I wonder if his own isolationist impulses will gradually override those worries as this latest build-up inevitably leads to a new round of stalemate.

Per Michael Warren, Trump’s national security team was in favor of a surge — except for Jeff Sessions, Trump’s nationalist kindred spirit, who argued that he should keep his campaign promise and bring Americans home from a war that seems unwinnable and in which most of the country long ago lost interest. The most interesting political wrinkle in tonight’s speech will be how Trump’s nationalist base reacts. Steve Bannon left the White House on Friday vowing to wage war against it — not against Trump, specifically, as that would inflict a lot of cognitive dissonance on the Breitbart base but on the “globalists” around him, like McMaster, who are supposedly leading him into misadventures. If Trump does in fact order a surge tonight, expect Breitbart and other populist media to flay McMaster over it. (Bannon reportedly had a huge blow-up with McMaster over this very issue during his last few weeks as a White House employee, in fact.) How’s Trump going to react to his biggest fans claiming that “Democrats” have seized control of his foreign policy and led it into a new dead end? We’ll probably find out tomorrow morning on Twitter.