Following the organization’s seventy-fifth anniversary, the conventional wisdom about NATO is that it is threatened by growing U.S. “isolationism.” Critics say that former President Trump could withdraw the United States from NATO if he is reelected. Controversy in Congress delayed supplying $60 billion in additional military aid to Ukraine. Trump has said that “he would encourage” the Russians “to do whatever the hell they want” to allies that fail to meet the 2 percent of GDP defense spending pledge. Some even express worry that the United States might withdraw its nuclear umbrella over Europe.

Overlooked in all this is that the attitudes of European allies about NATO and U.S. protection have always been variable. Just three years after NATO’s founding in 1949, Belgium, France, Italy, Luxemburg, the Netherlands, and Germany entered into a separate European Defense Community Treaty. The initiative reflected the vision of Jean Monnet, who dreamed of establishing a supranational organization for European defense. The idea of an integrated European military, led by a European defense minister, died in 1954 when the French parliament refused even to consider the concept—a harbinger of Gaullism and French skepticism about surrendering any defense responsibilities to a supranational organization, whether an Atlanticist or European grouping. 

Despite visions of an independent European defense alliance, NATO has been the mainstay of Western European security for over seventy-five years. Over that time, allies relied on the United States as NATO’s leader and dominant contributor. All Supreme Allied Commanders since NATO’s founding in 1949 have been American generals or admirals. The total population of NATO allies in Europe now exceeds 447 million. The European Union, composed mainly of NATO allies, constitutes the largest trading bloc in the world. The United States has remained, however, the military backbone of NATO, notwithstanding the vast European accumulation of wealth and resources since World War II.

Europe’s dependency on the American military has grown even greater since the end of the Cold War in 1989. Allies cut back their defense budgets in the years following, shifting those funds to finance social programs, the so-called “peace dividend.” Over two decades, Europe shed 35 percent of its military capabilities. Meanwhile, allies remained sanguine that the United States would continue to provide the bulk of protection for democracies in Europe, an assumption that has turned out to be accurate. At least until now, U.S. defense budgets have remained consistently higher in terms of GDP percentages than those of most European allies since the Soviet Bloc’s collapse.

As a result, when conflicts broke out in Bosnia and Kosovo in the 1990s, the United States had to take the military lead for NATO. Western Europe’s militaries were not up to the job, even against foes that were far less formidable than the former USSR. To even lead a NATO military coalition, U.S. diplomats had to wrestle first with the reservations of European allies led by France. They hesitated to bring any armed force to bear on a conflict in the heart of Europe without first receiving a UN Security Council resolution authorizing NATO military action. 

To the extent that Western Europe has taken any genuine interest in addressing its military responsibilities since the Cold War, it has done so as much or more through the European Union than NATO. In 1992, EU members agreed under the Treaty of Maastricht to set up a Common Foreign and Security Policy. Its missions included “the eventual framing of a common defense policy, which might in time lead to a common defense.” In 1999, the Member States of the European Council issued a declaration calling for a common and independent European policy on security and defense outside NATO. Javier Solan became the EU’s first High Representative for Common Foreign and Security Policy. 

To their credit, European allies did rise to the occasion after 9/11, invoking NATO Article V and supplying AWAC crews to operate along the U.S. Atlantic coast in the immediate aftermath of the attack. When, however, it came to fighting Al Qaeda and the Taliban in Afghanistan, NATO allies hedged their support with “caveats,” mostly declining to engage in offensive action against the Taliban alongside U.S. allies. The European drift from NATO accelerated in the late twentieth century when Brussels established the EU Political and Security Committee and the EU Military Committee. All these EU initiatives, providing for a separate defense relationship apart from NATO, began well before President Trump came on the national security scene.

As Brussels set up a new defense cooperation structure under the EU flag, Washington hoped that these initiatives might help speed the achievement of more European self-sufficiency in defense. That did not happen. As of 2023, a majority of allies still did not meet NATO’s agreed target of at least spending 2 percent of real GDP on defense. While more will likely reach that target in 2024, the reality is that most of those countries will be Eastern European and former members of the Warsaw bloc, not, for example, Germany, Spain, or Italy. 

What has spurred NATO momentum toward meeting two percent goals has been less President Trump and more the Ukraine War. Whether Trump returns to the White House or not, European allies have been mugged by the reality of Moscow’s conventional invasion of a country bordering NATO. Europe is finally beginning to realize that Washington has finite resources while facing mounting military demands around the world, including China, Taiwan, the Philippines, Korea, Iran, Iraq, Israel, Syria, and the Red Sea. One Biden administration official has been quoted as saying that the United States “is pretty maxed out…” Even without Trump, the United States can no longer be realistically expected to play as significant a future role in Europe as it has over the past seventy-five years. Far more than isolationism or the histrionics of a presidential candidate, the real dynamic causing Europe to reassess defense responsibilities is the realization that American military capabilities are increasingly overstretched. 

The issue today is how NATO, accepting this changing reality, must adapt for the future. A good start would be having a European general or admiral rotate regularly with an American flag officer as Supreme Allied Commander. Seventy-five consecutive years of an American SACEUR is enough. 

Another key step, made apparent by Ukraine, is that Europe must urgently build up its own military. Even a 2 percent GDP budget requirement will no longer be sufficient to this end. The United States spent about 3.4 percent of its GDP on military defense in 2023. During the Cold War, it spent from 5 percent to 10 percent of its GDP on the military. With Russia pawing at NATO Europe’s borders, it is finally dawning on allies that they must begin a crash defense buildup, as called for by NATO’s Secretary General. 

Finally, European allies must make up their minds about how the NATO alliance will have to work with the European Union on military matters. In a major strategic move, the EU just dispatched its own naval armada, Operation Aspides, to the Red Sea to defend commercial shipping from Houthi attacks. The EU’s independent task force is commanded by an Italian admiral whose flag is set in Athens. The European Union naval forces are acting only to repel Houthis missiles and drone attacks, not going so far as to attack Houthis positions. Meanwhile, a U.S. and British-led task force, Operation Poseidon Archer, is not only defending shipping from Houthis attacks but also launching offensive strikes against Houthis missile and drone sites. 

If the European Community wants to evolve into a more robust military organization, NATO’s role must be adjusted to leverage that reality. For example, it may be possible for some kind of special arrangement where the EU itself joins NATO in a hybrid partnership. As the military contributions of the United States to Europe decrease over time, allies could drift from NATO, focusing more on a regionally centered EU military alliance. For NATO to survive, European allies must be persuaded to remain committed to the thirty-two-member coalition even as the U.S. role becomes less dominant. 

Proving Macron wrong, that NATO is not “brain dead,” will be a challenge. Throwing more wood on that fire, President Macron just called for a stronger, more independent European defense policy, declaring that Europe must no longer be a U.S. “vassal.” Regardless, the North Atlantic Treaty Organization must continue its stabilizing role not only in Europe to contain Russia but also as an alliance capable of dealing with crises on its other peripheries. It must be prepared to act collectively as it has in the past in other regions, including the Middle East or even Asia, as it did in Afghanistan. America’s choices will be considerably less of a threat to the alliance and the continent’s future than Europe’s failure to adapt to a shifting world.

Ramon Marks is a retired international lawyer and Vice Chair of Business Executives for National Security (BENS).