Donald Trump’s foreign policy might be confusing and contradictory, but his comments on NATO stirred a debate on what benefits the United States receives from the transatlantic treaty.

NATO countries were “not paying their fair share,” The New York Times quoted Trump as saying.

“That means we are protecting them, giving them military protection and other things, and they’re ripping off the United States. And you know what we do? Nothing … Either they have to pay up for past deficiencies or they have to get out,” Trump said.

Trump’s willingness to question foreign entanglements have appealed to some libertarians, but it’s unclear whether he’ll win many of their votes. Rand Paul, the former candidate closest to libertarian Republicans, promised to support Trump if he becomes the nominee, which could boost Trump’s appeal.

Nick Gillespie, of Reason, expects most libertarians to go into hibernation for 2016, not having a clear candidate. Some libertarian might punt on a mainstream party and give the Libertarian Party a boost. Gary Johnson, the presumptive Libertarian Party candidate, polled at 11 percent in a Monmouth University poll in a hypothetical Johnson-Clinton-Trump race. Or they might favor Trump over his foreign policy and antipathy toward NATO and foreign intervention, if nothing else, according to Antiwar’s Justin Raimondo.

Evaluating NATO, however, isn’t as simple as Trump’s proclamations. The United States carries a heavier financial burden while Europe gets direct benefits, but the indirect benefits of a peaceful Europe are less clear.

“Trump’s complaints, and those of President Obama, about the ‘free riders’ of NATO such as Germany and France ignore the critical role the alliance has played for a host of smaller and far less prosperous nations since the end of the Cold War. Under the alliance’s tutelage, countries that might have lapsed into dictatorships or chaos instead became functioning democracies,” Jackson Diehl noted in The Washington Post.

Without the incentives of national security and access to markets offered through NATO and the European Union, the political will would have been weaker in central and eastern Europe to reform their economies and political societies.

Trump’s questioning of the status quo of NATO, as an expansionist Russia rises to upset the European order, begs the question of what his alternative would be.

To figure it out, he could turn to libertarians for guidance.

“America’s NATO policy is increasingly failing the most basic tests of relevance and prudence. It is well past time to conduct a comprehensive review and consider even the most drastic option: U.S. withdrawal from the alliance,” Ted Galen Carpenter, a senior fellow at the Cato Institute, wrote.

That could bolster his support among libertarians, even if his campaign is one of populism and dismissive of Constitutional principles. There’s little admiration for Trump among many libertarians, but with his comments on NATO, he might be able to persuade some of them to begrudgingly support him.