How Trump has already done irreparable damage to NATO
If the United States wavers, the entire alliance could crumble
The NATO summit this week was a high stakes event for President Trump.
NATO is a key component of the U.S.-led post-War international order that has made the world, on the whole, safer and more prosperous than in the past. Pax Americana — America's lone superpower status and web of security alliances and guarantees all around the world — deters great power conflict and enables global commerce to flourish.
And yet, Trump seems determined to undermine NATO. He already has, and will continue to do so.
Trump infamously called the NATO alliance "obsolete." He has repeatedly asserted that countries currently receiving protection from the United States should have to pay for it, as if it were a protection racket (the United States already gets a lot more out of those arrangements than it spends). More specifically, Trump has suggested that member countries that don't spend at least 2 percent of their GDP on defense (which is practically all of them) shouldn't get American protection in return.
It should be noted that this 2 percent "rule" is really, legally, a request; it's a good guideline and countries should obey it, but it's not an obligation under the NATO Treaty, and before Trump, nobody had ever suggested that not meeting this guideline would or could void the security guarantees under the Treaty.
On top of all this, there is the whole Trump-Russia soap opera. Depending on who you listen to, either Trump has a dovish view of Russia, or is a Russian agent; given that one of NATO's main jobs is to deter Russian expansion and that one of Russia's top foreign policy goals is to undermine NATO, this has been on everyone's mind.
Meanwhile, Trump has appointed to key national security positions experienced establishment hands, like Secretary of Defense Jim Mattis and National Security Adviser H.R. McMaster, both of whom have repeatedly and full-throatedly expressed U.S. support for NATO. In a way, this should be reassuring for anyone who believes in Pax Americana. But in another way, it only adds to the confusion, since nobody knows what the U.S. policy actually is.
With all that context, you can understand why the NATO summit was a big deal: What would Trump say and do that might shed light on what his actual views and policies are towards NATO?
Well, the NATO summit only deepened the confusion. Everybody was hoping to hear Trump's thoughts on Article 5, the provision that holds NATO together, since it states that any NATO country that is under attack will be defended by every other member country (given the U.S. superpower status, "every other member country" really means the U.S.). Indeed, that is the whole point of NATO: Its job is to deter foreign aggression against its members, since any member that is attacked will have the U.S. rally to its aid. But Trump had nothing to say about Article 5. He literally didn't mention it.
Many observers have taken this as a polite way of saying he doesn't believe in Article 5. White House Press Secretary Sean Spicer, however, has said this is a ridiculous interpretation, and that the U.S. stands by Article 5.
So the confusion endures. Trump says or does ridiculous things that would undermine massive amounts of foreign policy, and then people come up behind him to say, essentially, "Nevermind!"
Where does that leave us? At the risk of sounding crazy, it appears that NATO exists only really in our hearts. The whole point of NATO is deterrence. It works because the Article 5 provision is credible, because those who would attack NATO countries believe that the NATO alliance — and the U.S., specifically — would back it. The material things — the treaties, the U.S. military bases in Europe, the joint exercises, the missile defense systems, the summits — exist only to reinforce what is really the core asset and value, which is the psychological perception and belief, within NATO and outside it, that NATO "works" and that the president of the United States, whomever they might be, would in fact honor Article 5.
By putting this into question, Trump has already undermined NATO. If tomorrow Russian tanks rolled into Estonia, maybe Trump would come to Estonia's aid. Maybe Mattis and McMaster and others would convince him. But maybe not!
For deterrence to work, a "maybe" isn't enough. Your allies and opponents have to really believe that you believe in it. It's a psychological thing, a perceptual thing. And the very essence of Trump's character means nobody really knows what he truly believes or what he stands for. If tomorrow Trump tweets that he believes in Article 5, the damage is already done and will only worsen as long as he is the president of the United States.