What Trump Doesn’t Understand About NATO

Trump’s threat to defend only those NATO allies who pay enough for their defense makes no sense and reflects his fundamental misunderstanding of how NATO works.

Trump’s quick reversal on the tariffs he imposed on Canada and Mexico this week shows he doesn’t understand how the American economy works. The same is true for alliances like NATO.

Let me explain.

Trump seems to believe NATO is an alliance whereby European allies pay the United States to protect them. When he says they need to “pay up” or that Europeans “owe us billions,” he appears to think the United States gets paid to protect them. Given that Trump sees life as a series of transactions, that might make some sense.

But it’s just not how NATO works.

O is for “Organization”

When the 12 original members signed the North Atlantic Treaty in 1949, they committed to consider an “armed attack against one as an armed attack against all.” Should such an attack occur, every member committed to come to the defense of the country being attacked.

But a year later, following North Korea’s surprise attack on the South, the leaders of the countries that had signed up to the commitment realized that they needed to do more. They needed to have a political body in permanent session that could act swiftly in case of an attack. And they needed to have standing forces that could operate as a single military in order to respond to that attack.

Thus was born the North Atlantic Treaty Organization—a political-military institution, originally based in Paris, that was responsible for organizing and overseeing a standing military force that could respond as one in case of an armed attack. Nations appointed permanent representatives to the North Atlantic Council, the governing body of the new organization, and agreed to create an integrated military command structure headed by a Supreme Commander Allied Forces Europe (SACEUR). The first person to be appointed to that position was none other than Gen. Dwight D. Eisenhower.

Ever since, NATO has organized collective defense through an integrated process. Nations are responsible for fielding their own armed forces—ground, air, and naval—though an integrated defense planning process assigns each nation the kinds of capabilities and responsibilities they need to deploy. A Supreme Headquarters, Allied Power Europe (SHAPE), commanded by SACEUR, is responsible for planning, training, and, if necessary, commanding NATO operations.

This integrated defense planning and operational concept has guided NATO nations for the past 75 years. After the Cold War, some of the collective defense efforts were given shorter shrift, as member nations focused on peacekeeping operations in the Balkans and, ultimately, deploying a large NATO operation in Afghanistan following the September 11 terrorist attacks on the United States, which led it to invoke its Article 5 collective defense commitment for the first and only time.

After Russia’s full-scale invasion of Ukraine in 2022, NATO nations agreed to make collective defense and deterrence of an attack once again its priority mission. SACEUR was tasked with drawing up regional defense plans for defending NATO’s North, East, and South—something that hadn’t been done since the end of the Cold War. Those plans were approved by NATO leaders at their 2023 Summit in Vilnius.

SACEUR next developed overall force requirements for the implementation of these regional plans, and NATO members together decided how each would contribute to meeting these requirements. An updated set of NATO force needs will be presented to allied leaders at their Summit meeting in The Hague this June. The expectation is that in order to meet them, NATO nations will need to spend over three percent of their GDP, at least to be able to make the initial investments.

Defend All or None

On Thursday, President Trump repeated his oft-stated view that “if they don’t pay, I’m not going to defend them” referring to NATO allies. “It’s common sense.” But it’s not common sense, it’s plain nonsense.

NATO has institutionalized the principle that an attack against one is an attack against all though the process I use described. The focus of NATO’s efforts is to deter and, if necessary, defend against an attack against its territory. That’s how the plans are drawn up, the training is conducted, and the forces are commanded.

The United States cannot tell its armed forces to defend Poland but not Germany, because these forces are integrated into an operational structure designed to defend both. From NATO’s perspective, all of its members’ territory is a single theater of operations. Indeed, it was long assumed that this theater included the territory of neutral nations like Sweden and Finland before they joined NATO, since the defense of Norway and Denmark likely required the defense of those nations as well.

That is why Trump’s idea of defending some allies but not others is nonsensical. Like every other ally, Trump has two choices: he can opt to participate in the collective defense of NATO or he can decide not to do so. The first option is what NATO is all about. The second would mean the effective withdrawal from the Alliance.

When it comes to NATO, you’re either in or out. You can’t be half in and half out.