Bernie Sanders did not want to run a campaign on foreign policy. Now, after the attacks in Paris, he has to.

It’s clear that Sanders would rather focus on his longtime hobby horse: political revolution and class-based economics. “I understand there are some who think that because of this attack we no longer have the capability to address the collapse of the American middle class. I disagree,” Sanders said in a speech in Cleveland on Monday night. “Our country and the world can and will defeat Isis and at the same time, we will rebuild our disappearing middle class.”

The speech, in which he called for an international effort to “eliminate the stain of Isis from this world”, was Sanders’s first in-depth effort to address the issues surrounding Paris. During the Democratic debate, just 24 hours after the attacks, Sanders spent minimal time talking about the tragedy in his opening statement before abruptly segueing to his usual campaign talking points on domestic economic populism. What’s more, a Sanders aide had actively argued with the network hosting the debate, CBS, when the moderators signaled they would lead with a discussion of the terrorist strikes.

In in the two days between the debate and the Cleveland speech, Sanders tweeted roughly 30 times without mentioning terrorism, refugees, the Paris massacre or anything about foreign policy. He also held two campaign events in Iowa on Sunday during which he largely steered clear of the topic. While his rival Martin O’Malley criticized Hillary Clinton on foreign policy Sunday, Sanders’ campaign sought to push her on paid family leave.

Sanders aides insisted to Politico on Monday that he’ll have more to say on foreign policy soon, including a major military policy speech.

The senator’s lack of interest in foreign policy, long apparent, has never been more problematic than in the days following the deadly terror attacks in Paris. But it is not terribly surprising. After all, he’s been side-stepping criticism for his lack of foreign policy bona fides for the first eight months of his campaign.

Until September, Sanders didn’t even have a foreign policy page on his campaign website. And when his office blasted out a press release several days ahead of the first Democratic debate under the banner “Sanders foreign policy experience”, the contents focused exclusively on his vote not to go to war in Iraq, and offered no other policy-making insights.

The Democratic primary had, until Friday, been dominated by social and economic justice issues on which Sanders can shine. And, before Paris, just 2% of Democratic primary voters said terrorism was their primary concern, according to a recent NBC News/Wall Street Journal poll. But that’s changing.

The irony is that, back in the 80s when Sanders was starting his political career as mayor of Burlington, Vermont, foreign policy played an outsized role in his small town mayoralty. In his 1997 autobiography Outsider in the House, Sanders touted that Burlington was among the only cities in America to have a foreign policy. “Burlington had a foreign policy because, as progressives, we understood that we all live in one world,” he explained. And when the Reagan administration announced that it would back the rightwing Contras in Nicaragua, Sanders became the highest-ranking US official to go visit the country’s leftist leader, Daniel Ortega. The mayor even raised money to support the Sandinista government, earning him the nickname “Sanders-nista”.

Sanders has, if anything, become less interested in foreign policy over the course of his career – but even as mayor, his foreign policy was half-hearted. In thinking beyond the country’s borders, he was almost exclusively focused on visiting and fostering ties with countries maligned by Washington for their communist or socialist governments. In addition to his trip to Nicaragua, he traveled with his newlywed wife to the USSR and later visited Cuba, where he tried to meet with Fidel Castro. (He never did, but he did get an audience with the mayor of Havana.) And his other radical activities beyond the borders of Burlington were little more than symbolic gestures.

Even as he was leading the rare city with a foreign policy, the concerns of American workers still reigned supreme. In the summer of 1983, for instance, pacifist supporters wanted then Mayor Sanders to join calls to shutter a General Electric plant in Burlington because it was producing firearms being used to kill leftist forces in Central America, including the Sandinistas he had supported. But Sanders said no: he deemed the jobs the plant created domestically more important. That should have been a pretty clear hint as to how he would approach other foreign policy issues – as an afterthought to his economic agenda.

Almost three decades later, Sanders announced his presidential candidacy. In doing so, he’s driven discussions in the Democratic primary far to the left on issues like corporate power and income inequality. But on foreign policy, Sanders-nista is nowhere to be found. That may be in part because he recognizes that challenging a former secretary of state on foreign affairs and national security will inevitably be a losing proposition. But it is also almost certainly because, for Sanders, a class-based worldview trumps all, and a foreign policy outside of an economic justice framework is just something to which he hasn’t given much thought.

There’s also reason to think he’s not distinguishing himself from Clinton in this realm for the simple reason that he’s not very distinguishable from her on the issue. There are plenty of social-democratic types for whom ardent pacifism goes hand-in-hand with social justice-oriented economic policies – like Ralph Nader. But Sanders, it seems, doesn’t subscribe to those ideals: he frequently reminds people that he’s “not a pacifist” and, in particular, that he supported the war in Afghanistan.

Sanders didn’t spend years identifying as an Independent because there wasn’t a socialist party; he didn’t want to join it. As Annie Linskey wrote in the Boston Globe, Sanders insists that “his message resonates most loudly with blue-collar workers, not the tie-dye set” and that he would never own a pair of Birkenstocks “in a million years”.

If Sanders truly perceives his base to be blue-collar workers and not the radical left, as he says, he certainly wouldn’t want to alienate that base with tributes to pacifism or, as Huck Gutman, his longtime friend and former chief of staff, once put it, excessive concern for “the people far away”.

“He’s kind of a class prisoner that way,” observed Sanders biographer WJ Conroy, who presciently wrote a book with that thesis 30 years ago. (Conroy is now a professor of history and political science at Kentucky Wesleyan College.) But doesn’t class bleed into foreign policy? “It does,” says Conroy, “but those issues are so complex they can’t be reduced to the message of a capitalist society.”

How, for example, does class explain Isis? It doesn’t. And now Sanders may have to step away from the campaign message he’s spent decades honing.