It was a bad week for right-wing non-interventionists. The hodgepodge group of libertarians, pacifists, alt-righters, and paleocons had, for the part, latched onto Donald Trump’s campaign as a vehicle to smash the stranglehold of neoconservatives on the GOP and advance a stay-at-home foreign policy: no more wars in the Middle East, no interventions in the name of democracy or human rights or vengeance.

Trump became their man, when, in the midst of the Republican primaries, he did the unthinkable: He called Iraq “a disaster” and “a horrible mistake,” then accused the Bush administration of lying about weapons of mass destruction.

These were not shocking charges outside of Republican leadership circles. But inside, they were heretical. Trump had broken a taboo, much as Rand Paul had done a few years earlier, before turning away from his non-interventionist positions. Right-wing non-interventionists, hungry for a Paul replacement, were intrigued by Trump. In calling for easing tensions with Russia, scaling back security alliances like NATO, and staying out of Syria, Trump emerged as someone who would not only bash the neocons, but would champion the cause of non-interventionism.

As Tomahawk missiles streaked toward Al Shayrat air base in Syria last week, that all ended. It brought to mind a quote by Richard Viguerie, a leader of the New Right. Three weeks into the Reagan administration he fumed: “Most of us expected to be disappointed and get the short end of the stick. But I didn’t know it would be this short.”

The real question, in the wake of the Syria strike, is not why Trump decided to abandon his stay-out-of-it foreign-policy doctrine. It’s why non-interventionists put their faith in him in the first place. Trump has repeatedly shown he is neither a man of doctrine nor a man of his word. So why did so many believe that on this issue, he was both?

Trump latched on to a foreign policy slogan he barely understood

One explanation is that Trump’s choice of the campaign slogan “America First” resonated with the non-interventionist crowd. For candidate Trump, not exactly known for being versed in history or internecine conservative debates, it may have merely been a catchy slogan whose resonance was lost on him — even though it conveyed some of his inclinations. To non-interventionists, America First signified a coherent philosophy, a callback to the America First Committee of the 1940s.

When Trump first rolled out the slogan, historians and journalists reacted with alarm. In the years before the US entry into World War II, the AFC counted among its numbers figures like Charles Lindberg, a vocal anti-Semite, as well as members of the German-American Bund, an anti-Semitic American Nazi organization that propagandized on behalf of Adolf Hitler’s regime. Commentators retailed an ominous origins narrative involving bigoted isolationism and proto-fascism. It was not hard to find echoes of these sentiments in the dark tenor of the Trump campaign.

That story isn’t wrong, exactly. But that is only part of the story, one that non-interventionists argue neglects the respectable side of the non-interventionist tradition, which was also represented in America First.

Founded in 1940 at Yale by a group that included future President Gerald Ford and future Peace Corps founder Sargent Shriver, the AFC drew its membership from across the political spectrum. Its ranks included everyone from pacifists to Nazi sympathizers; it garnered endorsements from socialists like Norman Thomas to progressives like Robert La Follette to staunch conservatives like Robert E. Wood, chair of Sears Roebuck and the first president of the AFC.

Non-interventionists placed their shared goal of staying out of the war above other disagreements. Thomas, for instance, who was not a formal member of the AFC but often appeared under its banner, would speak with Charles Lindbergh despite Lindbergh’s anti-Semitism. Lindbergh was a celebrity, and Thomas believed that his popularity did helped the non-interventionist cause more than his anti-Semitism hurt it.

Despite these heterodox origins, the AFC would remain a touchstone for non-interventionists on the right far more than for those on the left. That’s because the group was generally more conservative than liberal, despite its foreign policy focus.

Though founded at Yale, it grew to be centered in Chicago, the heart of conservative Midwestern nationalism in the 1940s and 1950s. (Most of its 800,000 members came from within a 300-mile radius of Chicago.) The conservatism hardened over time: After the war, its president and major sponsors would go on to found conservative media outlets like the news weekly Human Events, long one of Ronald Reagan’s favorite publications.

Pearl Harbor made non-interventionism disreputable, yet that strand of conservatism persisted even into the Cold War

America Firsters believed their views were broadly popular, but that elites in politics and the media worked hard to suppress them. As evidence, they pointed to the 1940 election: The question of intervention had been taken off the table in the presidential race after Republicans nominated Wendell Willkie to face off against Franklin Roosevelt. (Non-interventionists preferred Midwesterner Robert Taft.) The tabling of the intervention debate struck non-interventionists as distinctly unfair: Whether to intervene in World War II was the most pressing issue of the day, yet there was no representative of the “no” view in the race.

The story was the same on the media front, they thought. The pro-intervention press beat the drums of war, countered only by a few staunchly nationalist papers like the Chicago Tribune and the New York Daily News. It was a classic populist complaint: the will of the people, thwarted by political elites and their cronies in the media. And if polls showed that the majority of Americans supported US intervention in the war, as they did by late 1940, well, that was the effect of an unprecedented propaganda campaign to sway their opinions.

The rest of the story is well-known. In December 1941, bombs rained down on Pearl Harbor. The US entered the war. The AFC disbanded.

Non-interventionists were out in the cold, and they would stay on the fringes of American politics, more or less, for a generation. There were right-wing non-interventionists who tried to infuse the emerging conservative movement with their beliefs. The three men behind Human Events, one of the first publications of postwar conservatism, all had ties to Quakerism and non-interventionism. The news weekly was infused with, if not pacifism, then a firm belief that the postwar order must be organized to prevent war.

They weren’t the only non-interventionists on the right. Economist Murray Rothbard championed an anti-war libertarianism, which ultimately won him the condemnation of conservatives like William F. Buckley, Jr., who believed anti-Communism had to include a willingness to use force to prevent its expansion, or even roll it back.

Indeed, as the Cold War emerged as the central organizing principle of American politics, the right-wing non-interventionists found themselves sidelined once again, as they had been during World War II. In an era when a loose consensus on New Deal-style governance dominated both major parties, conservatives were often denounced as part of the political fringe. That put right-wing non-interventionists on the fringe of the fringe.

To the extent that non-interventionism found a home in American politics during the Cold War, it was on the left, emerging from critiques of imperialism, capitalism, and racism that failed to resonate with the libertarians and nationalists that comprised right-wing non-interventionist. So for decades, they were left out in the cold.

It took the fall of the Berlin Wall to revive isolationism as a political force on the right

Given this history, it is perhaps no surprise that it took the collapse of the Cold War for right-wing non-interventionism to find a new place in American politics. Their unlikely champion? Pat Buchanan, who had turned to punditry after advising Presidents Nixon, Ford, and Reagan. After Ronald Reagan’s triumphant militarism and George H. W. Bush’s cautious realism — realism that nonetheless resulted in war in the Persian Gulf — Buchanan emerged as the new voice of the Old Right, a paleoconservative populist promoting a raft of nationalist policies, including non-intervention.

On the eve of his run for the Republican presidential nomination, Buchanan wrote the conservative publisher Henry Regnery to pitch his latest project: a new America First Committee. Regnery quickly agreed, and defended the first iteration of the group. “There can be no doubt, in my opinion, that the vast majority of Americans supported the aims of the America First committee, but the President and those who form public opinion, which is really the opinion of the few in a position to make themselves heard, were in favor of intervention. The rest, of course, is history.”

“America First” became Buchanan’s campaign slogan, as well. Like his AFC predecessors, Buchanan offered an alternative to intervention. But also like his predecessors, he mired the movement in a set of racist and anti-Semitic politics that made it difficult, if not impossible, to mainstream. In elevating Charles Lindberg as the group’s spokesperson, the original AFC showed an unwillingness to distance itself from racist and anti-Semitic figures. Fifty years later, Buchanan did the same.

In his years in politics, Buchanan has regularly found himself in the company of anti-Semites and white nationalists — trucking in Holocaust revisionism (he once suggested it was impossible that 850,000 Jews had been gassed at Treblinka), writing for the white nationalist anti-immigration site VDARE, and stating that “there are only two groups that are beating the drums for war in the Middle East —the Israeli Defense Ministry and its amen corner in the United States” (namely, Jewish neoconservatives).

Buchanan lost the 1992 primary, but his non-interventionist views remained a lively part of the foreign-policy debate on the right throughout the 1990s, especially as the Clinton White House embraced liberal interventionism, most notably in Bosnia. And Buchanan himself continued to seek the White House, running for the Republican nomination in 1996 and the Reform Party nomination in 2000, when his views on Jews (and African Americans) came under fire again.

In fact, one of his rivals for the Reform Party nomination in 2000 was especially aggressive in his attacks on Buchanan. He wrote that Buchanan “warns his followers that the United States is controlled by Jews, especially regarding foreign policy.”

“On slow days, he attacks gays, immigrants, welfare recipients, even Zulus. When cornered, he says he's misunderstood. … Buchanan is rewriting history and spreading fear for one purpose: To gain political power. That makes him a very dangerous man.”

The Reform Party candidate denouncing Buchanan? Donald Trump.

Trump challenged the neoconservatives in the Republican Party, and attracted a following for it

When Buchanan came out against the second invasion of Iraq, it made him persona non grata on the mainstream right. But it elevated him to hero status among right-wing non-interventionists. (Among left-wing doves, too: Buchanan had a long stint on MSNBC, helped by his opposition to the war.)

There was, however, virtually no space in Republican politics for a committed non-interventionist. From 2001 on, it was the neocon’s party. The quadrennial presidential candidacy of Ron Paul kept the dream of non-interventionism alive, but Paul’s dismal poll numbers did little to sway the party leadership.

Given the robust failures of the Iraq War and its deep unpopularity from 2005 on, there should have been some mix of soul-searching and power struggle among the party’s leading politicians and foreign-policy elites. But aside from Ron, and later Rand Paul, the voices of non-interventionism were largely absent.

There was a brief period in the early 2010s, dubbed “the libertarian moment,” when the advocates of non-interventionism seemed ascendant. But the rise of ISIS brought the hawks back to the fore, and even Rand Paul moved away from non-interventionism by 2015, rejecting the Iran nuclear deal and calling for strikes against Bashir al-Assad in Syria.

Enter Donald Trump. As Paul dropped the non-interventionist ball, Trump picked it up. As a candidate, Trump insisted the US should stay out of Syria, that Iraq was a dumb war, that the next president should, yes, put America first. More important than his statements was what happened next: He didn’t drop in the polls. Far from it.

That was enough for right-wing non-interventionists to give Trump a second look. Yes, it required ignoring Trump’s militancy, his desire to “bomb the hell out of ISIS,” to grab Iraq’s oil, to build up the military. But if there’s one defining feature of Trump supporters, it’s their ability to ignore a large percentage of what Trump says. On foreign policy it was no different, because one phrase rang out above all others: America First.

Trump liked the sound of that. No more “leading from behind.” No more putting American interests second. “I like the expression,” he told the New York Times in March 2016, before going off on a Dangerfield-esque rant about how America gets no respect. Trump had found a slogan, not a philosophy. His attachment to the phrase was largely disconnected from its longer history.

And yet history has a way of reasserting itself. With occasional exceptions, both parties have rejected non-interventionism, relegating it to the sidelines, refusing it a hearing. And now, within a few months of taking office, Trump has conformed to those foreign policy norms, meeting the Syria crisis with bombs and an unexpected rationale of compassion for the people killed in the recent gas attack.

Mainstream voices among right-wing non-interventionists, like Rod Dreher and Daniel Larison at the American Conservative, were dismayed by Trump’s decision to strike Syria. But so were people like Richard Spencer, the white nationalist leader of the alt-right; Paul Joseph Watson, the British conspiracy theorist who writes for Infowars; and Mike Cernovich, a social-media troll and conspiracist (author of The MAGA Mindset: Making YOU and America Great Again). Spencer held a small rally outside the White House to protest the Syria bombing, where protesters shouted “We want walls, not war!” and counter-protesters doused Spencer with glitter.

In their desperation to find like-minded candidates, principled non-interventionists have repeatedly made strategic alliances, ones that ignore party lines, governing philosophies, and odious forms of racism and tribalism. Thus the embrace of Lindbergh and Buchanan and Trump. Thus the refusal of many right-wing non-interventionists to distance themselves in any meaningful way from the alt-right, whose white nationalism is often non-interventionist as well as racist.

Non-interventionism is not inherently xenophobic, but it does attract xenophobes. The challenge for those who come to non-interventionism from a place of principle rather than racism is to distance themselves from their repugnant bed-fellows, rather than to ally with them. That task is made more difficult thanks to interventionists eager to place all non-interventionists into the “fringe” category.

Embracing questionable political figures as a way of advancing legitimate foreign-policy critiques is a trade-off right-wing non-interventionists have made again and again. They did so with Lindbergh, with Buchanan, with Trump. And now that Trump has shown how little his non-interventionist rhetoric meant, they are back in the wilderness — an exile they share with troubling allies like Richard Spencer.

Nicole Hemmer, a Vox columnist, is the author of Messengers of the Right: Conservative Media and the Transformation of American Politics. She is an assistant professor at the University of Virginia’s Miller Center and co-host of the Past Present podcast.

The Big Idea is Vox’s home for smart discussion of the most important issues and ideas in politics, science, and culture — typically by outside contributors. If you have an idea for a piece, pitch us at thebigidea@vox.com.