Sen. Bernie Sanders (I-VT), one of the Democratic Party’s frontrunners for the 2020 presidential nomination, has a consistent foreign policy thesis: income inequality and authoritarianism are intricately linked.

He’s of course unhappy with both major problems, so how to combat them? Create a global democratic movement that counters authoritarian leaders from Russia to Saudi Arabia as a way to improve the lives of billions around the world.

It’s a theme that Sanders, who some say leads the Democratic field’s foreign policy thinking, has struck time and time again.

During a September 2017 speech at Westminster College, Sanders argued that America must “take into account the outrageous income and wealth inequality that exists globally and in our own country.” Doing so “recognizes that our safety and welfare is bound up with the safety and welfare of others around the world,” he said.

Just over a year later at Johns Hopkins University in Washington, Sanders renewed his pitch to say “we need an international movement that mobilizes behind a vision of shared prosperity, security, and dignity for all people.”

And in a Saturday New Yorker profile in which Sanders made many of the same points, one of his foreign policy advisers said “he’s bringing those views on the importance of tackling economic inequality into foreign policy.”

Clearly, Sanders is not only trying to articulate how he’d handle foreign affairs as president, but also how he defines a progressive foreign policy in general. “The United States must seek partnerships not just between governments, but between peoples,” he said at Westminster College.

There’s no question that his broad vision is radical. “This really is a departure from traditional foreign policy statements to acknowledge that the troubles with the world political and economic order predate Trump and are far more structural,” said Paul Musgrave, a US foreign policy expert at the University of Massachusetts Amherst.

But the questions Sanders must answer — especially if he’s going to lead the Democratic pack on world politics — is what it would look like in practice and how he actually accomplishes it all.

The promise and peril of Sanders’s foreign policy vision

Sanders has offered two main clues as to how he would realize his worldview from the Oval Office.

First, to reverse the rise of authoritarian leaders, Sanders wants the US to distance itself from them.

In the New Yorker piece, the senator explained that the US shouldn’t pick sides in ongoing geopolitical feuds, like Saudi Arabia vs. Iran or Israelis vs. Palestinians. Instead, he would empower citizens — not officials — of those regimes who support better governance, progressive economic policies, and a more inclusive society.

That way, at least in theory, the US can influence the outcome without favoring unsavory leaders. “We’re not going to be spending trillions of dollars and losing American lives because of your long-standing hostilities,” he told the magazine.

The main concern experts I spoke to had is that this orientation may work for countries like Iran, which has a generally pro-American populace and a government that could, at least in theory, be coerced to change. But how would this approach help the people in an extremely authoritarian nation like North Korea, where many citizens can’t even access the internet, dislodge Kim Jong Un?

Sanders’s views may help the US extricate itself from worrying foreign entanglements — which experts generally applaud — but it may not fix some of the world’s most intractable problems.

Second, the senator also wants to support foreign governments who push back on multinational corporations that don’t pay enough in taxes and shift economic hardships onto working families. At the same time, he would champion trade policies at home that favor taxpayers over businesses.

In a sense, the senator wants to export his economic populist message and policies far and wide. But he may find some resistance from voters if he tries to change US economic practices to do that, Temple University’s Alexandra Guisinger, an expert on US economics and public opinion, told me. “That makes it an ‘us versus them’ issue,” she said, especially if he does something like lower tariffs on agricultural goods so foreigners can sell more to the American market.

Further, cracking down on rampant global capitalism — which Sanders derides — would mean mostly targeting developed countries, many of whom are US allies, she continued.

Musgrave had the same concern. “Financial firms in London, Geneva, and New York, including their intermediaries in places like the Caymans and the Channel Islands, play a big role in helping to preserve international oligarchs’ wealth,” he told me. “Presumably a President Sanders could deal with New York’s role in domestic politics — but how would he seek to shut down other countries’ financial networks?”

The biggest issue, per Musgrave, is that Sanders seems to think authoritarianism and oligarchy cause most of the world’s problems. “It comes a little close to a ‘Theory of Everything,’” he said.

Sanders’s challenge throughout the primary, then, will be to flesh out his global vision and translate it into tangible policies. Should he win the nomination, though, he will have to face another foreign policy hurdle: Trump.

Sanders’s Trump problem

During the 2016 presidential election, Sanders faced the widespread impression that his economic message — rebuild America instead of investing in wars — sounded an awful lot like President Donald Trump’s. Sanders may have that problem again this time around.

There are two main reasons why, Guisinger told me.

First, like Trump, Sanders is supportive of reforming free-trade agreements such as NAFTA — which reduced trade barriers between the US, Canada, and Mexico — to protect American industries. However, the senator doesn’t like Trump’s current effort to retool the accord.

“Go back to the drawing board on NAFTA,” Sanders said during a Saturday rally in Michigan. “Do not send this treaty to Congress unless it includes strong and swift enforcement mechanisms to raise the wages of workers and to prevent corporations from outsourcing American jobs to Mexico.”

Second, both the Democratic frontrunner and Trump are skeptical of international institutions. Sanders in particular worries about the International Monetary Fund (IMF), a world body that helps to keep the global economy stable.

When he was in the House of Representatives in 1998, Sanders famously grilled then-Treasury Secretary Robert Rubin on IMF loans to repressive governments. And in 2015, he blasted the IMF for imposing austerity measures on Greece as a condition to receive economic aid during its financial crisis.

“It is unacceptable that the International Monetary Fund and European policymakers have refused to work with the Greek government on a sensible plan to improve its economy and pay back its debt,” he told the Huffington Post at the time. “At a time of grotesque wealth inequality, the pensions of the people in Greece should not be cut even further to pay back some of the largest banks and wealthiest financiers in the world.”

It’s perhaps no surprise, then, that Sanders has expressly tied his economic message to democratization. After all, Trump has warmed to authoritarian leaders in Russia, Saudi Arabia, and North Korea while doing little to promote democracy around the world. Sanders, on the other hand, hopes improving the economic well-being of others will help growing democratic movements abroad gain steam.

It’s a theme one can expect Sanders — and other Democrats — to hit repeatedly during the campaign. The ultimate question then becomes if Sanders can truly carve out a new path for American foreign policy during the campaign, whether he wins or not.

“It’s a vision in which international economics would be subordinated to a vision of political relations and human rights that would be as big a departure from Clintonism as Trumpism, just in a different direction,” Musgrave said.