“Bernie is the only candidate who has a comprehensive foreign policy vision to stand up to the growing movement of anti-democratic authoritarianism worldwide and find solidarity with working people around the world who, in many cases, share common needs,” said Josh Orton, Sanders' national policy director. Another Sanders aide referred to his approach to international affairs as a “global struggle.”

Sanders has made clear during his campaign that he shares many of the left wing's long-held critiques of American imperialism — from opposition to clandestine interference across the world, but particularly in Latin America and the Middle East, to disapproval of the American military's global footprint. It's safe to say that a Sanders presidency would mark a dramatic departure from the last several decades of American foreign policy.

In recent weeks, he has been alone among Democratic presidential contenders in speaking positively about far-left leaders abroad. He said Bolivia's former president Morales “did a very good job in alleviating poverty and giving the indigenous people ... a voice.” Sanders argued that Brazil's Lula “has done more than anyone to lower poverty in [the country] and to stand up for workers." And the senator has drawn lofty parallels between his own campaign and recent mass protests in Chile, Lebanon and Iraq. In a high-profile speech in 2017, he criticized America's past actions in Iran, Chile, Vietnam, Latin America and Iraq as "just a few examples of American foreign policy and interventionism which proved to be counterproductive."

Warren, by contrast, has been more cautious on foreign affairs, straddling the line between the left and the Democratic foreign policy establishment. She has not been as definitive about the situation in Bolivia, where Morales was forced to resign under pressure by the military after allegations of election fraud in what Sanders deemed a "coup." Nor has she gone out of her way to praise and cultivate relationships with leftist figures around the world.

And while Warren has also cast her campaign as a movement, she has not drawn international parallels. She acknowledges mistakes of U.S. foreign policy but is less critical of American global leadership.

“There’s a story we tell as Americans, about how we built an international order — one based on democracy, human rights, and improving economic standards of living for everyone,” Warren said in a highly billed speech last year ahead of her presidential run. “It wasn’t perfect — we weren’t perfect — but our foreign policy benefited a lot of people around the world.”

Warren has been more hawkish than Sanders on China and more resistant to having talks with an Assad-led Syria and North Korea, positions that are more in the foreign policy mainstream. While Sanders considers Israel's Netanyahu government part of a growing "authoritarian axis," Warren will preface criticism of Israel by noting that it is a "strong and important ally."

Warren joined much of the Western world in expressing support for more aggressive action against Nicolás Maduro's government in Venezuela and recognizing Juan Guaidó as an interim president in 2019. Sanders declined to recognize Guaidó and urged the U.S. to "learn the lessons of the past and not be in the business of regime change or supporting coups.”

People in Sanders’ orbit attribute the shift in focus from 2016, when he didn’t talk as often about foreign policy, to the presence of his top foreign policy adviser, Matt Duss, a fierce progressive critic of Washington’s foreign policy establishment. Duss was previously president of the Foundation for Middle East Peace and has not worked in a presidential administration.

Warren’s top foreign policy aide Sasha Baker, Sanders allies point out, is a more traditional choice, having served as deputy chief of staff to Barack Obama’s Defense secretary Ash Carter.

Warren's worldview is most distinct when she ties it back to her message of the political and economic system being rigged. “Washington’s focus shifted from policies that benefit everyone to policies that benefit a handful of elites, both here at home and around the world,” she said in her speech last year.

Warren spokesperson Alexis Krieg told POLITICO that "Elizabeth believes that by pursuing international economic policies that benefit American workers instead of an elite few, and using diplomacy to amplify strong yet pragmatic security policies, we can achieve a foreign policy for all."

Sanders’ top aides and surrogates argue that his international, worker-focused vision makes him best equipped to take on the so-called “Blob," a term of derision for what is seen as bipartisan Washington group-think on foreign policy. Sanders has railed against establishment U.S. foreign policy since his time as mayor of Burlington, Vermont, in the 1980s — cultivating relationships with Nicaragua, Cuba and the Soviet Union — and his team believes only radical new leadership will avoid repeating past mistakes.

Critics say that despite Sanders’ talk about worker-led democracy and ending wars, many of the leftist leaders he has praised — such as Morales and, in the 1980s, Daniel Ortega in Nicaragua — are essentially authoritarians. (He has since criticized Ortega’s government as “anti-democratic.”)

“What we have in Latin America is not democratic socialism at all,” said Eduardo Gamarra, a professor of politics and international relations at Florida International University. “Sanders’ notion of democratic socialism which he says is that of Northern Europe is very different than that of the leaders he embraces.”

But such criticism has not fazed the Sanders team or his allies. “This isn’t about Bernie endorsing one particular leader’s ideology or political program, though some would like to present it that way,” said a Sanders aide.

In a video released by his campaign, Rep. Ilhan Omar (D-Minn.), one of his most well-known endorsers, said Sanders is “the only candidate that wants to make sure that we end our endless wars.” Sanders himself has touted on the debate stage that he hasn’t voted to authorize any of President Donald Trump’s defense budgets, a subtle jab at Warren, who did authorize one.

Sanders campaign co-chair Nina Turner pushed the contrast further last month, saying on Twitter that Sanders “is the only candidate who ... spoke truth on what’s happening on Bolivia."

Let's draw distinctions on foreign policy:

.@BernieSanders is the only candidate who:

-Spoke truth on what's happening in Bolivia - it's a coup!

- Recognizes the dignity of our Palestinian brothers and sisters.

- Led in the Congress to end the war in Yemen#DemDebates

— Nina Turner (@ninaturner) November 21, 2019

The rhetoric appeared to be an attempt to differentiate from Warren. She has been more equivocal on Bolivia in recent weeks after Morales' ouster. Warren initially drew scorn from some on the left with a safe statement calling for new elections. Pressed a few days later by The Intercept for a "Young Turks" video on whether it was a “coup,” she said it “sure looks like that.”

Their differences over foreign policy have also surfaced in the Senate.

In 2013, Sanders was one of the few liberal senators to vote against John Brennan to head the CIA — citing his concerns about drone warfare and civil liberties — while Warren voted for him. Sanders was also one of only two “no” votes, along with Republican Rand Paul, on a 2017 sanctions bill aimed at Iran, Russia and North Korea. Sanders said he was worried about endangering the Iran nuclear agreement.

Some progressives argue that Sanders' efforts have pushed Warren and other candidates leftward on foreign policy — and they hope he continues to do so. Warren has pledged on the trail to make a peace process with Palestinians a condition for continuing to provide aid to Israel.

“If Israel’s government continues with steps to formally annex the West Bank, the U.S. should make clear that none of our aid should be used to support annexation,” she said in October. Pete Buttigieg also said that month that the “aid needs to be compatible with U.S. objectives.”

“Just look at how Elizabeth Warren and Pete Buttigieg and other candidates have changed their tune on this issue,” said Yonah Lieberman, co-founder of the left-wing group IfNotNow. “Bernie Sanders is the only candidate who has said that he will have the Israeli government face consequences for the ongoing human rights violations of the occupation. I would like to see more candidates support that position because it’s the only morally sound position.”