On Monday, Republican frontrunner Donald Trump criticized the U.S. role in NATO, the Cold War alliance that has since expanded, echoing remarks in 2011 by then-Secretary of Defense Robert Gates.

Rival Sen. Ted Cruz (R-TX) blasted Trump, saying the Brussels terror attacks Tuesday proved NATO’s importance. Brussels is home to NATO headquarters.

Trump’s remarks, made in a meeting with the Washington Post editorial board, and in a one-on-one interview with CNN’s Wolf Blitzer, happened the day before the attacks.

Asked by the Post‘s foreign affairs columnist, Jackson Diehl, if NATO should expand, Trump replied, in part:

Look, I see NATO as a good thing to have – I look at the Ukraine situation and I say, so Ukraine is a country that affects us far less than it affects other countries in NATO, and yet we are doing all of the lifting, they’re not doing anything. And I say, why is it that Germany is not dealing with NATO on Ukraine? Why is it that other countries that are in the vicinity of the Ukraine not dealing with — why are we always the one that’s leading, potentially the third world war, okay, with Russia? Why are we always the ones that are doing it? And I think the concept of NATO is good, but I do think the United States has to have some help. We are not helped.

Charles Lane followed up: “I’d like to hear you say very specifically, you know, with respect to NATO, what is your ask of these other countries? … Because it’s not that you want to pull the U.S. out.” Trump replied:

No, I don’t want to pull it out. NATO was set up at a different time. NATO was set up when we were a richer country. We’re not a rich country. We’re borrowing, we’re borrowing all of this money. We’re borrowing money from China, which is a sort of an amazing situation. But things are a much different thing. NATO is costing us a fortune and yes, we’re protecting Europe but we’re spending a lot of money. Number 1, I think the distribution of costs has to be changed. I think NATO as a concept is good, but it is not as good as it was when it first evolved. And I think we bear the, you know, not only financially, we bear the biggest brunt of it. Obama has been stronger on the Ukraine than all the other countries put together, and those other countries right next door to the Ukraine. And I just say we have, I’m not even knocking it, I’m just saying I don’t think it’s fair, we’re not treated fair. I don’t think we’re treated fair, Charles, anywhere. If you look everything we have. You know, South Korea is very rich. Great industrial country. And yet we’re not reimbursed fairly for what we do. We’re constantly, you know, sending our ships, sending our planes, doing our war games, doing other. We’re reimbursed a fraction of what this is all costing.

Trump went on to say that “personally,” he does not believe the U.S. gains from having bases in South Korea and elsewhere, and cannot afford to maintain peace in the Pacific.

On CNN, Blister asked Trump: “Do you think the United States needs to rethink U.S. involvement in NATO?”

Trump replied in the affirmative:

Yes, because it’s costing us too much money. And frankly they have to put up more money. They’re going to have to put some up also. We’re paying disproportionately. It’s too much. And frankly it’s a different world than it was when we originally conceived of the idea. And everybody got together.

But we’re taking care of as an example the Ukraine. I mean, the countries over there don’t seem to be so interested. We’re the ones taking the brunt of it. So I think we have to reconsider, keep NATO, but maybe we have to pay a lot less toward the NATO itself.

Blitzer followed up by observing that U.S. allies would not be happy to hear his criticism. Trump responded: “Well, they may not be happy but, you know, they have to help us also.”

Blitzer again: “So you’re really suggesting the United States should decrease its role in NATO?”

Trump: “Not decrease its role but certainly decrease the kind of spending. We are spending a tremendous amount in NATO and other people proportionately less. No good.”

On the one hand, Trump is not saying anything new — or anything that has not been said already by the Obama administration. In 2011, Secretary of Defense Robert Gates made almost exactly the same criticism, noting that the U.S. pays a disproportionate amount (about 23%) of NATO’s expenses and bears much of the military burden. In fact, Gates warned specifically: “Future U.S. political leaders– those for whom the Cold War was not the formative experience that it was for me – may not consider the return on America’s investment in NATO worth the cost.”

On the other hand, however, for Trump to suggest that the U.S. reconsider its commitment to NATO, while at the same time criticizing the Obama administration for abandoning America’s allies, and while promising to build up the military, presents a puzzling set of potential contradictions.

NATO is regarded — by friend and foe — as an extension of American power, and diminishing it is hard to square with making America “great again.”