Listen to Republican presidential candidate Donald Trump discuss some of his foreign policy positions with The Washington Post editorial board. "NATO is costing us a fortune," Trump said. "We're not reimbursed fairly for what we do." (The Washington Post)

Donald Trump's attitude toward defense spending is a weird one. He wants to invest more money in the military, to make it so big and so strong that no one will "mess with us," but also he wants to reduce how much we spend on defense and also have the military do fewer things.

It's a cake-and-eat-it-too idea: A lot more for less to do a lot less but get more. The motivation seems to be that it's popular. A big tough army that doesn't cost us as much and that doesn't go around defending weird places like Albania or whatever? Sign me up.

As he revealed the first public members of his foreign policy team during a meeting with The Washington Post's editorial board on Monday, Trump unveiled a new facet of his plan.

Trump declared U.S. involvement in NATO may need to be significantly diminished in the coming years, breaking with nearly seven decades of consensus in Washington. "We certainly can’t afford to do this anymore," Trump said, adding later, "NATO is costing us a fortune, and yes, we’re protecting Europe with NATO, but we’re spending a lot of money."

To some extent, it's of a piece with his repeated assertions that others should pay us for our international military deployments. But, interestingly, NATO -- a collection of more than two dozen mostly-European countries -- actually goes out of its way to ensure that its member nations provide relatively equal resources.

Trump's statement that "NATO is costing us a fortune" depends on how you define "fortune." The 2016 budget for the organization outlines three cost buckets: The civil budget (personnel, etc.), the military budget (obvious), and an investment mechanism allowing the organization to build its own infrastructure. Combined, the annual NATO budget is just over 2 billion euros -- or $2.3 billion.


Portuguese special forces take part in a exercise as part of the NATO's Trident Juncture 2015 in Troia, 100 kms south of Lisbon on November 5, 2015. (FRANCISCO LEONG/AFP/Getty Images)

Of that, the United States is responsible for 22.1 percent of the costs, or about $514 million dollars. That's a fortune by average-American standards, but not by Trump standards, much less U.S.-government standards. The 2016 defense budget for the U.S. is $585 billion, meaning that this NATO expenditure is only 0.09 percent of the total. So for every $100 the military spends, nine cents is spent on NATO's annual budget. And for every $100 the government spends, only about a penny is spent on NATO.

There is an imbalance in the deployment of resources within NATO. If you combine the GDP produced by every NATO member, the United States is a little less than half. If you combine all of the countries' military spending, though, the U.S. is nearly three-quarters -- meaning that the U.S. is often the source of a lot of intelligence and infrastructure. (Though not necessarily 73 percent of it, per NATO.) NATO has a plan for member nations to up their defense spending, thereby broadly improving their military capabilities and making the organization less reliant on the U.S. Update: In 2011, Robert Gates gave a speech indicating that three-quarters of NATO defense spending was paid for by the United States, and that only five of the 28 NATO members were allocating the appropriate levels of spending on defense.

Update: Timothy Sayle, historian of NATO and postdoctoral Fellow at Southern Methodist University's Center for Presidential History, told us via email why figuring out the true cost of NATO is so tricky.

Throughout the Cold War, especially in the 1970s and after, Congress and the White House always disagreed about how much the US spent on "NATO." Congress would always give a high estimate (based on the cost of the U.S. soldiers deployed in the U.S., the cost of maintaining ships in NATO waters, etc.); the White House always argued back saying that the cost was much lower, arguing that the United States would need to maintain such forces even if there was no alliance commitment, and so they’d shave off some of the costs. The differences sometimes varied by enormous sums of money. ...

Essentially, because NATO rests on the belief and the expectation that the United States would come to the aid of any ally attacked, the costs are uncertain.

"Even though all Allies may not contribute forces to an operation," NATO's description of its funding reads, "Allies have agreed that the funding for the deployment of the NATO part of a NATO-led operation would be commonly funded." That's close to the Trump ideal.

What's not clear is how much of the resource allocation the United States spends on NATO would be in place even if NATO didn't exist, providing defensive capabilities to partners in Eastern Europe or to Turkey. After all, one of the points of NATO is to bolster military capabilities in places that are closer to strategic opponents and which may not have robust defenses of their own.

But, again, this is not a tough political play for Trump to make. In Pew Research polling from last summer, about half of Americans had a favorable view of NATO, down slightly from five years ago. Among Democrats, the figure was 56 percent; among Republicans, 43 percent. Interestingly, residents of the United States were more likely than countries in Europe to believe that we should send forces from our own country to defend an ally that was under attack from Russia. Fifty-six percent of Americans said that we should do so, compared to only 38 percent of Germans.

What's worth noting is that Trump's position is probably the most isolationist of any of the 17 people who once sought the Republican nomination. Sen. Rand Paul objected to granting NATO membership to Georgia and Ukraine, but he doesn't seem to have ever called for withdrawing from it.

There's probably a political lesson in that.