Here’s something you don’t know about John Bolton: He was the only foreigner — not just the only American, but the only foreigner — in the headquarters of Vote Leave when the Brexit referendum results came down in 2016.

True, his presence was accidental. The London studio used by Fox News just happens to be in the same building, and I had asked John in after bumping into him on the stairs. Still, it could not have been more apt from a symbolic perspective. No one has been a stronger defender of Brexit, and indeed of national sovereignty in general, than the man with the 1890s bartender mustache.

I don’t always agree with John. He is, as a rule, much readier to want to invade a place than I am. But there is no doubting the man’s patriotism, intellect, and integrity. America’s friends had a true champion in him, America’s foes a formidable adversary. Bolton espoused the reliably hawkish positions that American conservatives once took for granted: pro-Taiwan, anti-Iran, pro-sovereignty, anti-communist. President Trump must have known his views when he hired him, and Bolton has not wavered in them since. So why was he fired?

The short answer is that the two men kept disagreeing. Fair enough: If you never accept your national security adviser’s advice, why keep him around? But then, why hire him at all?

Did the Donald demand that Bolton publicly support a policy with which he disagreed? It would be in character. The present White House has something of the atmosphere of a medieval palace, with favorites jostling for the king’s attention. This particular monarch likes asking his courtiers to prove their loyalty by saying things that they find dishonest, distasteful, or discreditable. He seems not to like independence of character.

In 1967, Lyndon Johnson said of a potential White House appointee, “I don’t want loyalty. I want loyalty. I want him to kiss my ass in Macy’s window at high noon and tell me it smells like roses.”

If Trump expected that kind of loyalty, if he wanted Bolton publicly to contradict himself on talks with the Taliban or détente with North Korea, he had the wrong man.

Explaining the sacking, the president blamed Bolton for using the phrase “the Libyan model” when discussing North Korean denuclearization. The words were supposed to have upset Kin Jong Un. As Trump tells it:

We were set back very badly when John Bolton talked about the Libyan model. And he made a mistake. And as soon as he mentioned that, the Libyan model — what a disaster! Take a look at what happened to Gadhafi with the Libyan model. And he’s using that, to make a deal with North Korea? And I don’t blame Kim Jong Un for what he said after that, and he wanted nothing to do with John Bolton. And that’s not a question of being tough, that’s a question of being not smart, to say something like that.

Except that Bolton had not, by any stretch of the imagination, suggested military intervention or regime change in Pyongyang. What he had said was that the removal of nuclear weapons from North Korea had to be verifiable and complete, as in Libya rather than as in Iran. Asked whether the United States would insist on the complete removal of ballistic missiles and nuclear material from North Korea, he had replied:

“Yes, I think that’s what denuclearization means. We have very much in mind the Libya model from 2003, 2004. There are obviously differences. The Libyan program was much smaller, but that was basically the agreement that we made.”

Both Kim Jong Un and the Iranian leader, Hassan Rouhani, disliked Bolton. Rouhani, indeed, has publicly welcomed the removal of the man he blamed for keeping sanctions in place against Tehran. “Americans have to realize that warmongering and warmongers are not to their benefit,” he told Iranian TV viewers.

Maybe not. Then again, neither is a nuclear-armed Iran. A national security adviser is not supposed to be popular with anti-American dictators, for heaven’s sake. If they dislike him, he is doing his job.

The U.S. needs to pick its battles carefully. With a trillion-dollar deficit, it cannot afford to police every conflict or to maintain expensive garrisons around the world. I have some sympathy with Trump’s desire to retrench, and I can see the case for drawing the Taliban into a political process.

But even in a world where the U.S. seeks to do less, it will still have interests. It will still have allies who look to it for leadership. It will still have foes who want to harm it. Bolton understood that in his bones. America’s friends will miss him.