A good recent article at the Washington Post - John Bolton's Crusade to debunk Trump's revisionist history on Russia and Ukraine.
Some parts:
Yes, Trump’s former national security adviser John Bolton has turned on Trump like many others in Trump’s inner orbit have. His version of events is therefore understandably uncharitable. But if there were one thing that would seemingly earn the gratitude of an uber-hawk like Bolton, pretty high on that list would be Trump’s supposed success in keeping Putin in check.
Bolton has now said repeatedly that this simply isn’t how it went down. And he’s made quite the opposite case: that Putin didn’t do stuff like this during Trump’s presidency because Trump was already doing the work for him — specifically, by undermining NATO. And it’s a case that tracks with plenty of what we already knew, even as few Trump allies-turned-critics have seen fit to weigh in publicly of late.
In late February, Bolton appeared on Trump-friendly Newsmax and told a host who was pushing the Trump line that it was “just not accurate to say that Trump’s behavior somehow deterred the Russians.”
“In almost every case, the sanctions were imposed with Trump complaining about it, saying we were being too hard,” Bolton retorted when the host suggested that it was unthinkable that Trump would’ve handled the situation worse than President Biden has. Bolton added that Trump “barely knew where Ukraine was.”...
Asked whether we should believe this wouldn’t have happened on Trump’s watch, Bolton said, “Certainly not.” Bolton added that, in a second term unencumbered by future electoral considerations, Trump would’ve been even more freed up to potentially take the United States out of NATO.
“And so Putin would’ve gotten what he wanted in Ukraine for a lot lower price than he’s paying now,” Bolton said.
Then Bolton added, in perhaps his most unvarnished comment to date: “The Leninist phrase is ‘useful idiot,’ and they haven’t forgotten that in Moscow.”