UK Parliament / Jessica Taylor / Handout via Reuters

Tony Blair used to joke with his left-wing critics that the truth about him was even worse than they feared: His centrist policies weren’t just political positioning, he’d say; he actually believed in them. The same might be true of Boris Johnson and Brexit—with consequences far more profound than generally understood.

In the immediate aftermath of last week’s seismic general election, many commentators and analysts speculated that regardless of Johnson’s hard-line Brexit rhetoric, the outcome of his emphatic victory might actually be a “softer” departure from the European Union. Such was the scale of his victory, the argument went, that Johnson was now liberated from his party’s most euroskeptic wing. This meant that he was freer to negotiate a close future relationship with the EU, in which Britain would remain largely aligned with the regulatory standards set in Brussels in return for good market access. In other words, the economic turbulence of Brexit would be limited. Ultimately, these commentators argued, Johnson is a man of no real principle who will quickly turn on his more ideological colleagues once it becomes clear that he will be politically damaged by the economic impact of a “hard” break with Brussels.

Don’t hold your breath. While Johnson may yet prove his critics right and accept close economic alignment with the EU, doing so would undermine everything he has argued for and prioritized as a politician (and indeed, written about as a journalist). If his words and actions are taken at face value (admittedly a big if), last week’s general-election victory is unlikely to be the end of Britain’s Brexit drama. It will be only the beginning.

To understand why, it is crucial to remember that Britain’s departure from the EU is not a single act, but a process. While the country is now certain to formally leave on January 31, that is only the first stage of its disentanglement. Once Britain has withdrawn from the EU, it will enter a so-called transition period, in which it will continue to accept all EU rules and regulations in exchange for maintaining the economic status quo until a new trade deal is agreed on. In effect, nothing will change.

The problem is that the transition period, which runs until the end of 2020, is not long enough for much to be agreed on at all. Basically, unless the United Kingdom requests an extension to this period, something Johnson has categorically said he will not do, both sides have less than a year to agree on a trade deal, avoiding the imposition of tariffs, quotas, checks, and controls. Failure to do so would cause an economic shock to Britain, Europe, and the wider world. Because of the threat of such damage, many analysts believe that Johnson will eventually cave to whatever demands the EU makes, signing on to terms that maintain trade while binding Britain to the EU’s economic and regulatory order.

Those who have been involved in the Brexit negotiations or know Johnson are not convinced by that argument, though. On Brexit, Johnson appears to have one clear guiding principle: sovereignty. Brexit, in Johnson’s view, is fundamentally about self-governance and democratic control—the British government’s ability to do things differently from the EU and to be answerable to the British people for those decisions. He has argued that this, not economic integration, is the foundation on which Western prosperity is built and that, therefore, Brexit, if it is to mean anything, must be about the repatriation of economic self-governance. Were Britain to maintain a tight relationship with the EU, it would then have to sign on to the EU’s standards, and even, perhaps, be subject to European court rulings. One former diplomat who has worked closely with Johnson told me that even when Johnson was Theresa May’s foreign secretary, he would openly declare that the whole point of Brexit was to be able to diverge from Europe.

This is a stance on which he has been relatively consistent. As mayor of London, he wrestled with which side to back in the Brexit referendum before plucking for Leave. Why? In the Daily Telegraph column announcing how he would campaign, he claimed that it was because of “the inability of people to kick out, at elections, the men and women who control their lives.” Johnson said then, in early 2016, that Britain had “become so used to Nanny in Brussels that we have become infantilised.” When May proposed a future trading relationship after Brexit that would have seen Britain accept EU regulations without a vote on their adoption, Johnson quit her cabinet. He said at the time that May’s plan was only a "semi-Brexit" that would turn the U.K. into the "status of a colony.” Once he succeeded her, he negotiated a new Brexit deal, stripping out clauses that tied Britain to the EU labor market and the bloc’s environmental standards.

Taken to its logical conclusion, and given the limited amount of time to reach an agreement, Johnson’s philosophy suggests that there will be only the thinnest of trade deals between the U.K. and the EU—or indeed, no agreement at all. The EU has made clear that it will not countenance Britain maintaining open access to its market without making binding “level playing field” commitments to ensure that U.K. firms do not undercut their European counterparts on social or environmental regulations. This, in effect, means a Britain outside the EU agreeing to European standards, without any formal influence over what those standards are.

That there is such a fundamental disagreement about Johnson’s intentions goes to the heart of the man, one of the most poorly understood political leaders in recent memory. Ultimately, few people know who Johnson is, or what he believes, and so struggle to predict what he is going to do.

Those pushing the view that his decisive victory means he has more flexibility over Brexit dismiss him as a man of no discernible principle, other than self-elevation. This, of course, is not without foundation. As a student, he pretended to be left-wing; as a journalist, he was sacked for making up quotes; and as a politician, he has flirted with all wings of the Conservative Party without ever actually committing to one. Johnson appears to recognize his own political unfaithfulness. In his novel Seventy-Two Virgins the main character, who appears to deliberately resemble the author, worries that he only has a “knuckle of principle in the opaque minestrone of his views.”

Yet in the novel, when the time comes for him to stand up, to speak in defense of an American president being held hostage by a terrorist, Johnson’s protagonist summons the courage to do what he thinks is right (though, of course, it may also help him personally).

The moral of the story seems to be that Johnson himself might have few real principles, flirt with disaster, and always think of himself first, but that when push comes to shove, there is something underneath after all. To find out what that is, we may simply have had to listen to what he was saying all along.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.