Since the NATO summit and President Donald Trump’s follow-on bilateral meeting with Russian President Vladimir Putin last month, Europeans are asking themselves: Can we really count on U.S. defense commitments? Trump has made no secret of his disdain for the transatlantic alliance, including its foundational principle of collective defense that keeps Russia mostly at bay. He has openly talked about withdrawing the U.S. from NATO. While the European Union has steadily built a common defense policy and capability since the U.K. and France agreed to such authority in their 1998 declaration in Saint-Malo, France, Trump’s recent antics might have provided the necessary kick to accelerate and expand those plans.

Many European leaders have begun to argue that the U.S. cannot be the only solution to their security concerns. In an op-ed in the Washington Post, Radek Sikorski, Poland’s former defense minister and foreign minister, said the EU “needs an autonomous ability to defend itself … because the president of the United States is unreliable.” In the wake of the U.S. withdrawal from the Paris climate accord and the Iran nuclear deal, German Chancellor Angela Merkel has stated repeatedly that Europe cannot depend on the U.S. for military protection. In May, she said, “Europe needs to take its fate into its own hands.”

Some allies are backing up their words with new defense initiatives under the EU umbrella. Last year, 23 EU member states signed onto the Permanent Structured Cooperation (PESCO), a legally binding formalization of security cooperation intended to coordinate everything from defense policy to military procurement across the EU. In June, nine EU countries signed onto French President Emmanuel Macron’s proposal to create a European Intervention Initiative (EI2) that could be deployed to crisis regions in the Sahel and North Africa and would be open to U.K. participation, even after Brexit.

But EI2 still met some opposition within the EU from member states worried about duplicating NATO efforts, and it falls far short of an actual EU military force that would be prepared to take on the conventional defense of Europe without the U.S. European governments that have been unable or unwilling to spend more on their defense often have chosen to prioritize investment in niche military capabilities rather than acquiring the full range of forces and enablers that the U.S. provides through NATO.

U.S. Heft in European Security

The EU would be hard-pressed to replace or replicate U.S. contributions to European security. The U.S. spends 5 percent of its $602.8 billion defense budget on European defense, including a 22.1 percent share of NATO’s modest common budget, according to the International Institute for Strategic Studies. These figures are related but distinct from the much-discussed NATO goal for each member country to spend the equivalent of at least 2 percent of its GDP on defense, a target currently achieved by the U.S. and four other members.

More than 60,000 American troops are deployed to over 30 U.S. bases in Belgium, Germany, Greece, Italy, Norway, Portugal, Romania, Spain, The Netherlands, Turkey, and the U.K. The U.S. uses these forces to enable its military operations around the world, but their positioning also helps deter and defend against Russian aggression, and the bases support robust multinational training exercises, ballistic missile defense for Europe, and nuclear deterrence.

When NATO launches an operation or mission, members including the U.S. provide national personnel, equipment, and resources deployed under NATO command. While these contributions are voluntary, the U.S. has consistently provided a critical portion of troops and fills persistent capability gaps, including strategic enablers such as transport air craft, precision-guided munitions, and intelligence, surveillance, and reconnaissance (ISR) platforms.

Even during NATO operations in Libya in 2011, when the U.S. decided it would not take a lead role, it still launched 97 percent of the Tomahawk cruise missiles that took out Libyan air defenses at the start of the operation, and provided 75 percent of ISR data, 75 percent of the refueling aircraft, and 100 military personnel to the NATO targeting center to support NATO airstrikes.

Where does that leave the prospects of a real EU defense force without the U.S.? Simply put, the EU is not built for a conventional conflict with Russia—at least, not yet. The EU will have to be united in moving from crisis response and niche capabilities to conventional defense. That will depend on countries like France, Germany, and even the U.K. after Brexit providing a clear vision and an ambitious, but realistic, path forward for European defense.

EU Defense Gaps

EU members, combined, have about the same number of active duty military personnel and reserve personnel as the U.S.—1.4 million and 1.1 million respectively. EU countries will have to not only meet their commitment to spend 2 percent of GDP on defense, but exceed that level to pay for costly procurement of critical equipment. EU members combined have less than half the U.S. total of aircraft and aircraft carriers, and they will have to invest in more modern fighter and transport aircraft, ISR, and aircraft carriers.

Greater European self-reliance for military security also will require reevaluating the role of NATO with a disengaged U.S. NATO has been the world’s most successful and enduring military alliance, so most European allies will continue to see it as their best defense against Russian aggression. But they might need to calculate whether Trump is just a sign of a larger, underlying nationalism in the U.S. that will outlive his presidency, or whether, even if the U.S. commitment to NATO returns to normal after a Trump administration, the outlook still could be rocked in the future by another, similar political disruption in the U.S.

If Europeans believe they cannot rely on the U.S., building a joint military capability under the EU that can take over the defense of Europe may be their only recourse. But rather than dissolving NATO, that might mean a role reversal, in which the transatlantic alliance slips to a policy coordination body, perhaps with a crisis management function, and the EU takes over responsibility for the defense of Europe.

Even with a unanimous shift in priorities within the EU, European countries will not have the resources to build two duplicative military structures. It will take much more than simply increasing defense spending. Realistically, it will take the next five years for the EU to agree on a way forward and a level of ambition, and to do the kind of serious force planning needed to determine the capability gaps with an absent US and how to fill them. It will also take time for member states to push through the tough budgetary decisions that will be called for in their national capitals to secure needed funding for critical procurement projects.

In many ways, NATO allies are used to the American “bulldozer” style of diplomacy they are seeing under Trump, though it now has reached unprecedented levels. The Bush administration often treated the allies like a punching bag on Iraq and Afghanistan to secure at least political support, if not troops commitments from allies to assist in US operations there. The Obama administration regarded NATO with a friendly disinterest, focusing instead on his “Asia pivot.”

Even with Trump’s open antagonism for the alliance, some allies may wait in hope of a friendlier American administration. There are tough conversations to be had in Brussels, and soon, about what the EU will do if allies come to see the Trump administration as a sign of an increasing and irreversible decline in the U.S. commitment to European security.

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