President Obama told the BBC last year that he supports Prime Minister David Cameron's campaign for Britain to remain in the European Union. (Susan Walsh/AP)

As President Obama visits London this week, he is finding himself at the center of a very British controversy. The U.S. president has become a surprisingly important player in Britain's passionate "Brexit" debate — with his views even earning him the title "most anti-British American president there has ever been," coined by a well-known politician.

For the uninitiated, "Brexit" is the catchy portmanteau used to refer to Britain's potential exit from the European Union. After years of growing public dissent over the country's E.U. membership, Britain is set to have a referendum this summer on whether to remain in it. If a majority of Brits vote to "leave" the E.U., Britain will exit the bloc.

Exactly what happens after that isn't clear, but Obama evidently doesn't want to see it happen. “The European Union doesn’t moderate British influence – it magnifies it,” Obama wrote in a frank editorial that was published in London’s Daily Telegraph. “A strong Europe is not a threat to Britain’s global leadership; it enhances Britain’s global leadership.”

Obama's intervention in the Brexit debate had been widely expected. Last year, he had told the BBC that he supports Prime Minister David Cameron's campaign for Britain to remain in the E.U., adding that the membership gave Washington greater confidence in the transatlantic alliance and helped make the world “safer and more prosperous."

However, Obama has faced a serious backlash from Brits who are part of the "leave" campaign. So, why are they so mad? There seem to be three common arguments against Obama's Brexit intervention:

1. Foreign leaders shouldn't comment on another country's domestic affairs.

In a letter signed by 100 members of Parliament, former Conservative cabinet minister Liam Fox argued that Obama should not interfere in the Brexit debate as it has "long been the established practice not to interfere in the domestic political affairs of our allies and we hope that this will continue."

2. The United States would never agree to be a part of the E.U., they argue, so why should Britain?

The chief proponent of this argument is Boris Johnson, the mayor of London and a leading figure in Cameron's Conservative Party. In March, Johnson accused the United States of "exorbitant hypocrisy," saying it was in no position to preach because it defended its own sovereignty with "hysterical vigilance." He doubled down on this statement recently, saying it was "bizarre" to be lectured by the Americans when they "won't even sign up to the international convention on the law of the seas, let alone the International Criminal Court."

Other prominent figures within the Conservative Party have supported this view: Former cabinet minister Iain Duncan Smith recently said that voting to leave the E.U. would make Britain "look a little more like the U.S." Duncan Smith also suggested that if Washington liked the E.U. so much, perhaps it should join the bloc.

3. Obama hates the British.

It was Nigel Farage, the eccentric leader of the anti-E.U. U.K. Independence Party, who said that Obama is the "most anti-British American president there has ever been." This is almost certainly untrue, but it taps into a wider belief that maybe Obama just doesn't really like Britain that much.

This belief dates to at least 2009, when the British media criticized the new president for apparently sending a bust of Winston Churchill back to Britain. (As The Washington Post's Fact Checker column recently explained, the reality of this situation was a lot more complicated.) Johnson also drew on this argument in an article published in the Sun tabloid this week, suggesting to his readers that the "part-Kenyan President" had an "ancestral dislike of the British empire."

Adding fuel to the fire, Obama recently appeared to criticize Cameron, reigniting debate over the U.S. president's apparently cold view of Britain and what that says about the future of the "special relationship" between the two countries.

The logic here seems to go that Obama's hatred for Britain makes him want to keep the country in the E.U., where it will suffer forever more. Or, perhaps more mundanely, Obama could just be acting out of self-interest and be indifferent to what happens to Brits.

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It's pretty easy to chip some holes in these arguments, however.

For one thing, a Brexit vote isn't just a domestic affair. It really does affect Americans, too. London has long served as a voice for Washington in Europe, sharing not only a language but also perhaps an ethos bred by the close ties between the countries. If a Brexit actually happens, the United States will lose its top E.U. ally — and perhaps have to find another one. Where this would leave London is unclear: The United States is not keen to pursue new bilateral free-trade agreements, U.S. Trade Representative Michael Froman said recently, and instead favors multilateral free-trade platforms.

More broadly, the United States is concerned about the potential effects a Brexit could have on the world economy — the International Monetary Fund has warned that there would be "severe regional and global damage" if Britain leaves the E.U. And at a time of growing global concern about terrorism, experts have suggested that a Brexit would create serious security problems for Europe and, by extension, the United States.

Obama acknowledged this line of reasoning in his Telegraph editorial. “We are friends who have no fear of each other,” he wrote. “So I will say, with the candor of a friend, that the outcome of your decision is a matter of deep interest to the United States.”

Second, it's certainly true that the United States has shied away from a lot of international legislation. "All countries try to guard their sovereignty and maintain their freedom of action, but the United States is the world’s only superpower, so it has more go-it-alone power than any other country," Michael Beckley, an assistant professor of political science at Tufts University, said in an email.

But it's also more complicated than Obama's Brexit critics portray it. In the case of the U.N. Convention on the Law of the Sea, also known as the Law of the Sea Treaty, it was signed by President Bill Clinton in 1994. However, Congress has repeatedly refused to ratify it, as it has many other international treaties. The case of the International Criminal Court is a little different, but it is still not quite as Johnson has described: Clinton signed the Rome Statute that would lead to the creation of the ICC, but successor George W. Bush refused to ratify the statute and effectively "unsigned" it by declining to work with the court.

It hardly seems fair to blame Obama for this. The president has attempted to get the United States more involved in international treaties, pushing Congress to ratify treaties that have been signed and trying to find inventive ways to get around congressional opposition in other cases. And although he hasn't gotten the Rome Statute ratified, he has reestablished a working relationship with the ICC. Meanwhile, Obama is leading a push for the United States to join a huge free-trade agreement, the Trans-Pacific Partnership. (How TPP actually gets ratified by Congress is a whole other issue, however.)

Finally, Obama's supposed hatred of the Brits is a little hard to see in action. He doesn't seem to have made any substantive changes to the special relationship in the seven years he has been in office, other than some not-so-thinly veiled criticism about Britain not pulling its weight on the world stage. Perhaps more important, polls have shown that he is widely respected and liked by Brits — in particular, the younger generations expected to turn out in droves for the Brexit vote.

Ultimately, that might be the real reason that Obama's thoughts on Brexit are proving so controversial in Britain: They may well carry more weight than the opinions of Britain's own leaders.

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