Over the summer, I interviewed several dozen people about what the United States could expect from Donald Trump’s first term. Campaign advisers shared his plans, his associates relayed conversations, and I consulted veterans of five Republican Administrations, along with economists, war gamers, historians, legal scholars, and political figures in Europe, Asia, and Latin America.

Most of the people I spoke with outside the campaign expected Trump to lose. But they also expected his impact to endure, and they identified examples of the ways in which he had already altered political chemistry far beyond the campaign. After seventy years of American efforts to stop the spread of nuclear weapons, Trump has suggested that South Korea and Japan might be wise to develop them. Returning from a recent visit to Seoul, Scott Sagan, a political-science professor at Stanford who is a nuclear-arms specialist, told me, “These kinds of statements are having an effect. A number of political leaders, mostly from the very conservative sides of the parties, are openly calling for nuclear weapons.”

Many of Trump’s policy positions are fluid. He has adopted and abandoned (and, at times, adopted again) notions of arming some schoolteachers with guns, scrapping the H-1B visas admitting skilled foreign workers, and imposing a temporary “total and complete shutdown of Muslims entering the United States.” He has said, “Everything is negotiable,” which, to some, suggests that Trump would be normalized by politics and constrained by the constitutional safeguards on his office. Randall Schweller, a political scientist at Ohio State University, told me, “I think we’re just at a point in our history where he’s probably the right guy for the job. Not perfect, but we need someone different, because there’s such calcification in Washington. Americans are smart collectively, and if they vote for Trump I wouldn’t worry.”…

When Trump talks about what he will create and what he will eliminate, he doesn’t depart from three core principles: in his view, America is doing too much to try to solve the world’s problems; trade agreements are damaging the country; and immigrants are detrimental to it. He wanders and hedges and doubles back, but he is governed by a strong instinct for self-preservation, and never strays too far from his essential positions. Roger Stone, a long-serving Trump adviser, told me it is a mistake to imagine that Trump does not mean to fulfill his most radical ideas. “Maybe, in the end, the courts don’t allow him to temporarily ban Muslims,” Stone said. “That’s fine—he can ban anybody from Egypt, from Syria, from Libya, from Saudi Arabia. He’s a Reagan-type pragmatist.”