Sebastian Rotella reports on how many of the people that worked with Bolton remember his tendency to distort intelligence and ignore facts that contradicted his assumptions:

“Anyone who is so cavalier not just with intelligence, but with facts, and so ideologically driven, is unfit to be national security adviser,” said Robert Hutchings, who dealt extensively with Bolton as head of the National Intelligence Council, a high-level agency that synthesizes analysis from across the intelligence community to produce strategic assessments for policymakers. “He’s impervious to information that goes against his preconceived ideological views.” [bold mine-DL]

That assessment lines up with what I understood about Bolton, and it points to one of the biggest problems with his appointment. I wrote this shortly before Trump announced that he was choosing Bolton:

The real danger is that he is such an ideologue that he would keep information from the president that contradicts his views and prevent Trump from getting the best available advice. Trump is poorly informed to begin with, and having Bolton as his main adviser on matters of national security and foreign policy would make sure that he stays that way.

Trump is especially susceptible to being manipulated by his advisers into endorsing the policies they want because he knows so little and responds so favorably to flattery, and he has shown that he is already more than willing to select a more aggressive option when he is told that it is the “presidential” thing to do. We should expect that Bolton will feed Trump bad or incomplete information, present aggressive options in the most favorable light while dismissing alternatives, and praise Trump’s leadership to get him to go along with the hard-line policies Bolton wants. Bolton will run a very distorted policy process and he will be the opposite of an honest broker. That won’t serve Trump well, and it will be terrible for our foreign policy.