The One Time NATO's Article 5 Was Invoked, and Who Answered the Call

The next time somebody at a barbecue tells you that NATO has never done a thing for America, ask them one question: what happened on September 12, 2001? Watch the face. Most people do not know. Most people have never been told that the only time in its history the North Atlantic alliance invoked its sacred mutual-defense clause, the one that says an attack on one is an attack on all, it did so on behalf of the United States of America.

Not for Poland. Not for Germany. For us. A generation of Americans has grown up hearing that allies are freeloaders and that the treaty is a one-way street, and there is a kernel of truth in some of that, which we will get to. But the whole story is better, and more useful to a conservative, than either the sneer or the sentimentality. So let's tell it in order, from the founding to the airplane radar patrols over American cities, and then ask what a Republican should conclude.

The world of 1948

Start with the room in which the treaty was born. By early 1948 Europe was a continent of ruins. In February the Communists took full control of Czechoslovakia in a coup. In March, Britain, France, Belgium, the Netherlands and Luxembourg signed a mutual defense pact in Brussels, because they were frightened and knew they could not defend themselves without American help. In June the Soviets blockaded the road, rail and water routes into West Berlin. Everyone could see the pattern.

America, meanwhile, had a tradition. Washington's farewell address warned against permanent alliances, and the country had spent most of its history taking him at his word. The idea of a peacetime military alliance with European powers was, in 1948, one of the more radical proposals in American history. It would take a President of one party and a Senate leader of the other to pull it off.

Vandenberg does the unglamorous work

The leader was a Republican, Arthur Vandenberg of Michigan, who chaired the Senate Foreign Relations Committee when his party controlled Congress in 1947 and 1948. Vandenberg had been one of the great isolationists of the 1930s. Then, in a Senate speech in January 1945, he announced that Pearl Harbor had ended the possibility of isolation, and from then on he became the partner of President Truman in building the postwar order. He is credited with the phrase that politics should stop at the water's edge, and he acted like it.

On June 11, 1948, the Senate passed what became known as the Vandenberg Resolution, which stated that the United States would associate itself with regional collective defense arrangements, subject to constitutional processes. It was not a treaty, and it committed no troops. What it did was clear the legal and political path. It showed the European governments that the Senate, and not just the White House, was prepared to talk. That is the sort of work that does not get statues, and it was the hinge on which the whole alliance turned. When people say conservatives have no tradition of building institutions abroad, point them to the man from Michigan.

Reading Article 5 the way the Senate read it

The North Atlantic Treaty was signed in Washington on April 4, 1949, by twelve nations: the United States, Canada, Britain, France, Belgium, the Netherlands, Luxembourg, Italy, Portugal, Norway, Denmark and Iceland. The famous clause is Article 5. In substance it says that an armed attack against one or more of the parties in Europe or North America shall be considered an attack against them all, and that each of them will assist the party attacked by taking "such action as it deems necessary, including the use of armed force."

Read that phrase again, because it is where the conservative case for the treaty starts. The words are not "will send troops." They are "such action as it deems necessary." The drafters deliberately left each member free to decide how to respond, and the Senate cared a great deal about that. The Constitution gives Congress, not the President alone, the power to declare war. Senators did not want to sign a blank check, and they did not. Article 11 adds that the obligations are carried out according to each country's constitutional processes. The treaty is a promise of solidarity, not an automatic trip-wire for war.

I want you to notice something about this design: it is a conservative document. It respects national sovereignty and the separation of powers. It does not create a supranational authority. It is an agreement among free nations to stand together, with each one keeping the final say. And it worked because everyone, especially the Soviets, understood it meant what it said.

April 4, 1949, and the dissent of Robert Taft

Not every Republican was convinced. Senator Robert Taft of Ohio, "Mr. Republican," voted against the treaty. He feared that it would provoke the Soviets and commit America to an open-ended arms race, and he worried about the burden on the taxpayer. He was not a fool, and his objections are the foundation of a conservative school of thought that is still alive. They are laid out in Taft Versus Eisenhower and the Republican Fight Over the World, which is worth reading if you want to understand how this argument inside the party has run for three-quarters of a century.

The Senate gave its consent in July 1949, and the treaty entered into force in August. A British officer, Lord Ismay, who became NATO's first Secretary General, is supposed to have said that the purpose of the organization was to keep the Soviet Union out, the Americans in and the Germans down. It is a good line, and whether or not he said it in exactly that form, it captures the early logic. The alliance was supposed to hold the line in Europe with American weight behind it.

A clause that never had to be used

Here is the irony. For the entire Cold War, through the Berlin crises, the Soviet invasion of Hungary and Czechoslovakia, and four decades of tanks facing each other across the German plain, Article 5 was never invoked. That is not a failure. It is the entire point. The clause was a deterrent, and a deterrent that works is a deterrent that is never used. No Soviet planner ever had to be shown what would happen if the Red Army crossed the line. They could read the treaty, and they could count the American troops stationed there. The logic is the one explained in Why Deterrence Is a Promise You Have to Be Willing to Keep.

Then the Cold War ended, the Soviet Union dissolved, and people assumed the clause would be a museum piece. It was not.

September 12, 2001

On the morning of September 11, 2001, nineteen hijackers took four airliners and killed nearly three thousand people at the World Trade Center, at the Pentagon and in a field in Pennsylvania. The NATO ambassadors met the next day, September 12. They agreed that if it was determined that the attack was directed from abroad against the United States, it would be regarded as an action covered by Article 5. For the first time in the history of the alliance, the clause was invoked, on the day after the worst attack on American soil since Pearl Harbor.

The determination was made formally a few weeks later. On October 2, 2001, after American officials briefed the allies on the evidence that the attacks were directed by al-Qaeda from Afghanistan, NATO's Secretary General, Lord Robertson, announced that the conditions had been met. On October 4 the allies agreed to a package of measures to support the United States, including intelligence sharing, access to ports and airfields, and blanket overflight rights.

Think about what that means. The countries of Europe, who had spent half a century relying on American protection, were saying, in the most formal language the treaty has: we are with you. They were also, by the way, volunteering. Washington had not asked for the invocation, and one of the odd features of the episode is that the American government did not initially take the allies up on all of it. The early campaign in Afghanistan was run largely by the United States, with allied special forces and help from a handful of partners, and the Pentagon's attitude was that the mission should determine the coalition and not the other way around. That is a defensible military preference, and it also left some allies feeling that the offer had been politely turned aside. A good friend will notice when the favor is declined, and will remember it.

Who actually answered the call

But there was more than a gesture. In the weeks after, NATO's own airborne early-warning aircraft, the AWACS radar planes, with crews drawn from several allied countries, flew patrols over American airspace so that American aircraft could be sent to other duties. This operation, known as Eagle Assist, lasted from the autumn of 2001 into the spring of 2002. It meant that the sky over American cities was being watched in part by Canadians, Germans and other allied crews. In the Mediterranean, the alliance launched a naval operation, Active Endeavour, to monitor shipping and deter terrorist movements.

And then came Afghanistan itself. From 2001 on, allied troops fought there, and in August 2003 NATO took command of the International Security Assistance Force in Kabul, its first major operation outside Europe. Soldiers from Britain, Canada, France, Germany, Denmark, Poland, Italy and many other allied countries served in Afghanistan, and many of them died there. They fought in the places no one remembers the names of, in valleys most Americans could not find on a map, for a mission that began with an attack on New York. I do not think the fallen of those countries should be forgotten when someone calls NATO a charity case.

The best objection, and the answer

Here is the argument against, stated as fairly as I can. Skeptics say that Article 5 was a one-time symbolic gesture. They say that European militaries were thin, that many allies came to the fight with restrictions on what their troops could do, and that the real work was done by the Americans. They say the Europeans have for decades under-spent on defense while counting on American protection, and that invoking Article 5 for the United States cost the Europeans little, because we were the ones with the capacity to respond. Some add that the Afghan war ended badly and that the alliance followed us into it.

There is truth in all of that. Some allies did place limits on what their forces could do, and the alliance's spending record is a legitimate grievance, covered at length in Burden Sharing Is Not a Trump Idea, It Is an Eisenhower Idea. The answer is in three parts.

1. Quality of effort and quantity of effort are separate questions. A smaller ally that sends its soldiers into a war that was not its own, and buries them, has done something real. The measure of an ally is whether it shows up when you are hit, not whether it matches your budget.
2. The grievance is a reason to fix the alliance, not to scrap it. If a partner is underinvesting, the answer is to push, with the same arguments Eisenhower used and Congress has used since. Walking away from a sound structure because the tenants are behind on rent is poor housekeeping.
3. The alternatives are worse and more expensive. An America that faced the next crisis without allies, without bases in Europe, without the habits of cooperation built over seventy years, would pay far more, in dollars and in risk. And the war it is easiest to fund is the one you never have to fight.

An asset that has to be kept in repair

So what does a Republican conclude? That alliances are assets, and assets depreciate if you ignore them. A treaty is not self-executing. It needs credibility, and credibility needs forces, exercises, shared planning and, above all, members who pay their share. It needs a President who says what the commitment is and means it, and a Senate that does its job on treaties. It needs our side to say plainly to the allies: you asked us to stand with you in 1949, we asked you to stand with us in 2001, and both of us owe the other the courtesy of being ready.

It also means being honest about the limits. NATO is not a universal police force. The reason it works is that its promise is clear and its membership is defined. If you want to see how the American approach to the wider world plays out in the context of the Cold War victory, look at George Kennan's Long Telegram and the Strategy That Won the Cold War, and for a modern reminder of what happens when a security promise is vague, see What America Promised Ukraine in 1994 and What It Did Not.

The bottom line

• The mutual-defense clause of the North Atlantic Treaty has been invoked once, on September 12, 2001, and it was invoked for the United States.
• The treaty was built with a Republican hand, Senator Arthur Vandenberg's, and it respects American sovereignty: each member decides "such action as it deems necessary."
• Allies flew radar patrols over our cities and sent soldiers to Afghanistan. Those who criticize NATO should say so first and then make their case about spending.
• The right answer to a freeloading ally is pressure and reform, not abandonment. An alliance that is kept in repair is the cheapest defense we have.
• When someone tells you allies are worthless, ask them what they think the 2001 volunteers earned. Then ask what they would put in the place of the treaty.