In the early summer of 2017, a little less than a year after his Presidential campaign had ended, Bernie Sanders spent a few days on a speaking tour in England, to promote the European version of his book “Our Revolution.” The Brexit resolution had passed twelve months earlier, a general election looked likely to consolidate the conservative hold on the country, and Sanders’s audiences—in the hundreds, though not the thousands—were anxious and alert. I was at those events, talking with the people who had come—skinny, older leftists and louche, cynical younger ones—and they were anticipating not just the old campaign hits but a broader explanation of why the world had suddenly gone so crazy and what could be done. Sanders had scarcely talked about foreign affairs in his 2016 campaign, but his framework had a natural extensibility. Under way in the world was a simple fight, Sanders said. On one side were oligarchs and the right-wing parties they had managed to corrupt. On the other were the people.

In the thirty months since Sanders’s 2016 campaign ended, in the petulance and ideological strife of the Democratic National Convention, he has become a more reliable partisan, just as progressivism has moved his way. He begins the 2020 Presidential campaign not as a gadfly but as a favorite, which requires a comprehensive vision among voters of how he would lead the free world. In 2017, Sanders hired his first Senate foreign-policy adviser, a progressive think-tank veteran named Matt Duss. Sanders gave major speeches—at Westminster College, in the United Kingdom, and at Johns Hopkins—warning that “what we are seeing is the rise of a new authoritarian axis” and urging liberals not just to defend the post-Cold War status quo but also to “reconceptualize a global order based on human solidarity.” In 2016, he had asked voters to imagine how the principles of democratic socialism could transform the Democratic Party. Now he was suggesting that they could also transform how America aligns itself in the world.

In early April, I met with Sanders at his Senate offices, in Washington. Spring was already in effect—the cherry blossoms along the tidal basin were still in bloom but had begun to crinkle and fade—and talk among the young staffers milling around his offices was of the intensity of Sanders’s early campaign, of who would be travelling how many days over the next month and who would have to miss Easter. It was my first encounter with Sanders during this campaign. Basic impression: same guy. He shook my hand with a grimace, and interrupted my first question when he recognized the possibility for a riff, on the significance of a Senate vote on Yemen. His essential view of foreign policy seemed to be that the American people did not really understand how dark and cynical it has been—“how many governments we have overthrown,” as Sanders told me. “How many people in the United States understand that we overthrew a democratically elected government in Iran to put in the Shah? Which then led to the Revolution. How many people in this country do you think know that? So we’re going to have to do a little bit of educating on that.”

One condition that Americans had not digested was the bottomlessness of inequality. “I got the latest numbers here,” Sanders said. He motioned, and Duss, who was sitting beside him, slid a sheet of paper across the table. “Twenty-six of the wealthiest people on earth own more wealth than the bottom half of the world’s population. Did you know that? So you look at it, you say”—here he motioned as if each of his hands were one side of a scale—“twenty-six people, 3.6 billion people. How grotesque is that?”

He went on, “When I talk about income inequality and talk about right-wing authoritarianism, you can’t separate the two.” No one knew how rich Putin was, Sanders said, but some people said he was the wealthiest man in the world. The repressive Saudi monarchs were also billionaire Silicon Valley investors, and “their brothers in the Emirates” have “enormous influence not only in that region but in the world, with their control over oil. A billionaire President here in the United States. You’re talking about the power of Wall Street and multinational corporations.” Simple, really: his thesis had always been that money corrupted politics, and now he was tracing the money back overseas. His phlegmy baritone acquired a sarcastic lilt. “It’s a global economy, Ben, in case you didn’t know that!”

When Sanders’s aides sent me a list of a half-dozen foreign-policy experts, assembled by Duss, who talk regularly with the senator about foreign policy, I was surprised by how mainstream they seemed. Joe Cirincione, the antinuclear advocate, might have featured in a Sanders Presidential campaign ten or twenty years ago. But Sanders is also being advised by Robert Malley, who coördinated Middle East policy in Obama’s National Security Council and is now the president of the International Crisis Group; Suzanne DiMaggio, a specialist in negotiations with adversaries at the Carnegie Endowment for International Peace; and Vali Nasr, the dean of the Paul H. Nitze School of Advanced Studies at Johns Hopkins and a specialist in the Shia-Sunni divide.

Few of these advisers were part of Sanders’s notionally isolationist 2016 campaign. But, as emergencies in Libya, Syria, and Yemen have deepened, the reputation of Obama’s foreign policy, and of the foreign-policy establishment more broadly, has diminished. Malley told me, “Out of frustration with some aspects of Obama’s foreign policy and anger with most aspects of Trump’s, many leaders in the Party have concluded that the challenge was not to build bridges between centrist Democrats and centrist Republicans but, rather, between centrist and progressive Democrats. That means breaking away from the so-called Blob”—a term for the foreign-policy establishment, from the Obama adviser Ben Rhodes. DiMaggio said, “The case for restraint seems to be gaining ground, particularly in its rejection of preventive wars and efforts to change the regimes of countries that do not directly threaten the United States.” She and others now see in Sanders something that they didn’t in 2016: a clear progressive theory of what the U.S. is after in the world. “I think he’s bringing those views on the importance of tackling economic inequality into foreign policy,” DiMaggio said.

Since the 2016 campaign, Sanders’s major foreign-policy initiative has been a Senate resolution invoking the War Powers Act of 1973 in order to suspend the Trump Administration’s support of Saudi Arabia’s military campaign in Yemen. Mike Lee, a libertarian Republican from Utah, and Chris Murphy, a Democrat from Connecticut, co-sponsored the resolution; on April 4th, it passed in the House and the Senate. It was the first time that Congress invoked the War Powers Act since the law’s creation, in the aftermath of the Vietnam War. When we met, Sanders said that he thought the Republican support for the resolution was significant, in part because it reflected the strain of conservatism that is skeptical of military interventions. It also demonstrated, he believed, “a significant mind-set change in the Congress—Democrats and Republicans—with regard to Saudi Arabia.” He added, “I don’t see why we’d be following the lead or seen as a very, very close ally of a despotic, un-democratic regime.”