U.S. President Donald Trump’s mixed signals on defense guarantees to Europe have played into the hands of those on the continent who feel that the EU remains incomplete as long as NATO acts as the ultimate guarantor of European security. Adherents to this school of thought have drawn further encouragement from German Chancellor Angela Merkel’s call for Europeans to “take our fate into our own hands.” Add to this the manifest intention of France and Germany to focus on EU defense as a way to reenergize the Berlin-Paris axis, and the stage appears set for the EU to assume the collective defense duties that NATO seems to be abandoning.

At the June 22–23 EU summit, heads of state and government apparently obliged by activating a clause of the EU treaty that allows groups of member states to tighten cooperation on defense and act on behalf of the EU (with the approval of the rest). Countries have three months to agree on who is allowed to join a group and what it will do. The European Commission, not to be outdone, announced in time for the leaders’ meeting an expanded European defense fund to support collaborative military research and acquisition. All in all, there is more energy and interest in European defense cooperation than at any time since 1999–2004, when the present institutional architecture of European defense was established.

This would suggest the EU is busy replacing NATO, or trying to, but the real story is more complicated. The recent steps can equally be traced back to a shared frustration in Europe with waste and inefficiency in defense procurement, and to a more general shift in Europe toward differentiated levels of cooperation. Concerns about the reliability of U.S. guarantees do play a role, but a subtle one; they have breathed new life into initiatives that were previously stalled.

For an example of how this process works, consider the creation of an EU defense core, approved by EU leaders on June 22–23. This idea was attempted once before but was aborted after EU countries disagreed on who should join and why. The UK and a number of other EU countries saw the core as a threat to NATO; other EU states, suspecting they would not qualify on account of their low defense spending, blocked the initiative to avoid being ostracized.

Things could be different this time. Many EU countries have raised defense spending and begun to modernize their armed forces in response to Russia’s aggression toward Ukraine. This should make it easier for more countries to qualify for the core group, which could win new adherents among EU countries. Some Central European states that opposed the idea the first time around, seeing it as an affront to NATO, will now be tempted to join.

This renewed interest is not due to Trump but is because the likes of the Baltic states or Slovakia suspect that Western European countries want to leave them behind as they forge tighter cooperation on banking or taxation. Those newer members that want to be on the inside regard defense cooperation as price to pay for their entry.

Only recently have decisionmakers started to think of the core defense group as part of a response to Trump. Defense thinkers in Europe are quietly beginning to consider what may take NATO’s place if the United States erodes the credibility of the alliance. There is no good replacement for U.S. firepower, but the emergence of a core group of the most willing and capable European military powers is better than no alternative.

Apart from the defense fund and core defense group, there is little additional specificity on what the EU should do on defense that it is not already doing. This could come with time. Trump has been in power for only five months, and for much of that period, Europe has lived under the illusion that the U.S. secretaries of state and defense, rather than the president, would run U.S. foreign policy. As the reality of Trump’s disruptive potential sinks in, expect the politics of European defense to change further. Many European governments will become more reluctant to send troops to Afghanistan or tighten EU-NATO cooperation, because those decisions would bind them closer to Washington. Ideas that favor European defense autonomy will become more popular.

The challenge for Europe will be to distinguish between the steps necessary to better position Europe to cope with U.S. uncertainty and those that merely satisfy Europe’s periodic urge to have its security and defense identity reaffirmed in opposition to the United States. Given the renewed interest in Europe in defense and the possibility of more related initiatives, two guideposts can be helpful.

First, EU leaders need to be lucid about the challenges posed by President Vladimir Putin’s Russia. Only NATO fields the high-end capabilities needed to deter and defend against this resurgent threat in Europe’s neighborhood. The generation of the required military means for high-intensity military operations through capability development and defense planning should therefore continue to reside with the alliance. The fact that leaders concluded in June that the EU should identify “capability projects” to be covered by the European defense fund is hence of some concern.

Second, observers have already identified much work that will need to be completed to strengthen Europe’s role in managing operations below the level of collective defense. A key example is the need to deliver greater defense output through intensified cooperation in research and acquisition. This objective seems well served by the European Commission’s initiative, which seeks to boost economic and industrial cooperation through cash incentives. Both NATO and the EU stand to benefit—as long as European funds will not tempt EU member states to reduce national defense procurement budgets.

Marc Bentinck is a senior research fellow at RAND Europe and a former Dutch diplomat.