Along the campaign trail, Donald Trump said a number of things that concerned prominent Democrats and foreign leaders. Some of these things can be chalked up to campaign rhetoric, but few of these remarks made the heads of foreign governments wiggle uncomfortably in their chairs more than his stance on NATO.

In what would become a controversial series of statements made to the New York Times during his campaign, President-elect Trump explained that, under his administration, the military might of the United States may not be forthcoming to the other members of the NATO alliance in their times of need. Trump went on to explain that, while the United States has always been one of the primary financiers of the organization, not all member nations are contributing as they should be.

Among foreign leaders and American Democrats, these statements were seen as sacrilege. The North Atlantic Treaty Organization dates back to 1949, when its founding members chose to combine their political and military strengths to present a unified front against Soviet (read: communist) expansion, prevent the revival of nationalist militarism the likes of which the world encountered in both world wars, and encourage the political integration of European and North American nations. In effect, the organization was intended to prevent a third world war, in large part by rebuking what was then seen as the most likely candidate to start it: the Soviet Union.

So why on Earth would Donald Trump take such a controversial stance on such an important and historically significant organization? In the face of a new era of Russian posturing, Chinese naval expansion, North Korean nuclear weapons, and wars in multiple theaters, what could possibly lead America’s president-on-standby to consider weakening alliances with other nations? The world seems primed for conflict and sparks in Syria, the South China Sea, and Iraq could all feasibly light the fuse. Why, now more than ever, would we choose to stop honoring the agreements we’ve made with friendly nations?

Well, in part because those nations already stopped honoring them.

In much of the media, Trump’s statements were intentionally conveyed in a manner that made his stance seem like a protection racket run by mobsters. Trump said the U.S., under his administration, would only intervene on behalf of other NATO nations if those nations had “fulfilled their obligations to us.” This statement was percieved to mean that Trump would only protect our NATO allies if those countries were willing to pay for the service. As a candidate that was already depicted in the media as a cold-blooded shark-like businessman, many were disgusted at the concept that we’d charge our sister nations “protection money,” but in truth, that was never Trump’s stance.

President Trump calls on NATO to meet financial obligations to strengthen alliance

Read Next: President Trump calls on NATO to meet financial obligations to strengthen alliance

Article 5 of the Washington Treaty is seen as the core, guiding principle behind NATO as an organization. It states plainly that an attack against one ally is seen as an attack against every member of the alliance. NATO invoked this article after the September 11th, 2001 terrorist attacks on the United States, providing immediate military and political support to America in the wake of the disaster. It’s important to note, however, that the level of the support each member nation is required to provide is not laid out specifically in the charter, only that each nation must take “action as it deems necessary, including the use of armed force.”

Opponents of Trump’s position cite this cornerstone principle of the alliance as damning evidence that he either doesn’t understand the nature of the organization or has so little respect for NATO and its members that he believes he can dirty-business his way into granting America increased negotiation leverage. Neither are true (at least entirely). In truth, there’s another part of NATO’s charter that has been ignored by a number of politicians in recent years, dating back to well before Trump was even taken seriously as a candidate: the GDP requirement for all of NATO’s members.

NATO’s charter lays out military spending requirements for each nation within the alliance. The requirement is based on each nation’s economy and overall spending to ensure that all members of the organization share an even stake in the defense of themselves and one another. This benchmark financial requirement is two percent of each member’s gross domestic product.

Because the requirement is based on each nation’s GDP (gross domestic product), it means smaller nations with weaker economies put in less money than larger, more powerful nations like the United States. This leveling of the playing field does mean larger nations take on a larger role in the defense of the organization as a whole, but these larger nations are still only contributing two percent of their overall worth, and therefore can financially sustain the bigger burden. It’s the fairest way to produce the most powerful alliance possible.

The United States has been fulfilling this requirement and then some for years. Although NATO mandates a two percent defense expenditure annually, America spent 3.61 percent in 2016, and likely will match that in 2017. This $66.4 billion is the oft-cited defense spending left-leaning political figures in the nation constantly talk about reducing and reallocating. It also makes the American armed forces account for a whopping 72 percent of the military spending among NATO allies. Beyond that, America picks up the tab on 22 percent of NATO’s common expenditures, leaving the remaining 78 percent to be divvied up among NATO’s 27 other members.

All of this American spending would be fine if each NATO ally also participated by allocating two percent of their respective GDPs to defense spending as well. The problem is, they don’t. As Americans and foreign dignitaries yell at Trump for even suggesting he would violate one of the principles of the alliance, only four other nations even bothered to fulfill their financial requirements to the alliance in 2016.

Greece, Poland, the U.K., and Estonia are the only nations other than the United States to devote the required minimum spending to defense according to NATO’s charter. The remaining 24 nations chose not to meet the requirements set forth by the treaty organization, often allocating only half of their share of the overall cost of defense within the alliance. Spain, Canada, Belgium, and Slovenia didn’t reach half. Luxembourg didn’t even reach a quarter of their part of the tab.

So when Donald Trump suggests that America may not fulfill their part of the NATO alliance because other members aren’t fulfilling “their obligations,” he isn’t suggesting that Italy pay the United States for its services, or the Trump campaign for his support. Trump is saying that if we agree to fulfill the part of the NATO agreement that puts American lives in danger, the member nations we risk our soldiers, sailors, and Marines in support of should have to follow the rules too. In exchange for our unyielding allegiance to the articles NATO is founded upon, we should expect the same level of commitment from our fellow members.

In the geopolitical climate of today’s world, maintaining military and political alliances around the globe are of the utmost importance, and I would fervently disagree with a decision to leave NATO or the United Nations solely on the grounds that we should always strive for a unified approach to international conflict, but we must not be so blinded by our need for international support that we begin to use a different measuring stick when comparing U.S. investments in global security to those of other nations. Our success means we can carry more of the load, but a fair share is still a fair share.

I wouldn’t argue that we should ever violate the terms of NATO’s agreement, but I’m not opposed to someone holding their hand to the fire from time to time and reminding them that we’re all in this together.

Image courtesy of Politico