I think he'd fold, say it's not the US's problem, and also reap a big (maybe justified) I-told-you-so about NATO's low defense spending.

> Maybe he'd fold, maybe he'd go direct to nuke.

I don't think the president of the US has the authority to nuke anything by his own accord.

You are, unfortunately, mistaken. The President has sole authority over launch decisions. There is a requirement that those orders be verified as authentic by the Secretary of Defense, but assuming POTUS gave the orders, it's not within SecDef's authority to countermand them. What would actually happen if an insane POTUS were to give a launch order that made no sense is probably up to chance and the quality of those willing to break the law and refuse the order.

https://en.m.wikipedia.org/wiki/Nuclear_football

"However, the President's authority as Commander-in-Chief is not unlimited and US law dictates that the attack must be lawful and that military officers are required to refuse to execute unlawful orders, such as those that violate the Laws of Armed Conflict."

Those laws are very very vague and like you said, it's possible someone in the chain of command could argue it's against the law since a nuke would likely cause collateral damage one way or another. I think it's technically incorrect to definitively say that the US president has complete and total control over nuking a target.

Hey, wasn't this the EXACT argument Democrats made about removing Trump from office before the election? Floating the idea he'd risk WW3 instead of losing an election?

Turns out Trump's general hard line on everything was useful for something.

the President can order nukes to launch. there's no law curtailing that power, and military orders are the purview of the Executive under the Constitution, so it's doubtful Congress could even prevent that.

the nuclear football is basically a fancy sat phone though, so it's less clear if the generals who get the war order would actually obey.

Thinking highly of opponents of the US and spouting off about how smart and savvy they are never seemed to stop Trump from treating them like opponents and using his power against them back when he was president, so I'm not convinced it would if he was still in charge - and it certainly wouldn't be safe for them to rely on that.

> Recent mutterings suggest Trump thinks highly of Putin though, so it's hard to tell.

Care to provide a source for this?

If you're referring to the podcast where Trump mentioned that Putin's move (annexation of Lugansk & Donetsk) is "genious", that's not some sort of fanboyism or admiration, but simply admitting that the move, tactically, was really good - a lot of people (myself included) did fall for it!

Here are some mutterings https://www.huffingtonpost.co.uk/entry/trump-putin-pretty-sm...

>“He’s taking over a country for $2 worth of sanctions. I’d say that’s pretty smart,” Trump said at his Mar-a-Lago resort in Florida, according to New York Times reporter Shane Goldmacher and video footage obtained by the pro-Democratic group American Bridge. “He’s taking over a country, really a vast, vast location, a great piece of land with a lot of people, just walking right in.”

That's the quote I had in mind.

To anyone with basic reading comprehension, it's obvious that Trump isn't praising Putin, he's praising Putin's tactics, which, judging by the (lack of) response from the West, is pretty smart!