Relatively recently, the idea of a Unified European Defense Force — separate from NATO and under the direct command of the European Union — has become more prominent in mainstream European political discourse. Given President Trump’s relentless criticism of Europe’s commitment and consequent value to NATO, could there be room for this new, autonomous source?

A Brief History

To understand the current European dilemma, it is important to understand the history of Europe’s defense policy. Following World War II and the defeat of the German hegemon (a potent, lingering fear), the West’s greatest threat came from a Soviet invasion across Europe. In 1948, America and her allies formed NATO as a counter-balance to Soviet military power. NATO’s well-known Article 5, which states that an attack on one is an attack on all, signaled American resolve to defend its allies from Communist invasion or influence. This was consistent with the Truman Doctrine and American policy of containment towards the Soviet Union.

As the Cold War continued and the nuclear-arms race entered full swing, America extended its nuclear capabilities to defend allies (a “Nuclear Umbrella”). The U.S. decision to create a nuclear umbrella was not out of altruism, but out of self-interest: The U.S. sought to limit the number of nations with nuclear weapons (more proliferation meant more checks against U.S. power) and maintain European reliance on American security guarantees. This meant that, during the Cold War and to this day, the United States ensured security to its European partners.

Today Is Not Yesterday

The Cold War is over; new security threats have arisen; NATO membership has grown from 12 members to 29; and yet Trans-Atlantic defense policy remains remarkably similar. The result of an American security guarantee in a post-Cold War world has led to a moral hazard for many NATO members: Why spend on defense when we know the U.S. will defend us? This line of thinking has resulted in almost all European NATO members falling short of their pledged defense spending of 2% of GDP. While former Presidents have pushed NATO allies to increase spending, no credible stick has meant that NATO member spending remains below the 2% mark. Trump is the first President in decades to credibly threaten allies to increase spending. This has come from his original rhetoric of calling NATO obsolete and openly questioning if he would assist nations that have not met their spending targets. The possibility of a Europe left to defend itself forced European security experts to experience a mini existential crisis.

The idea of Unified European Defense Force — commonly referred to as the Permanent Structured Cooperation on Security and Defense or Pesco — is simple: Europe would maintain a unified military that would act separately from – but still adhere to – NATO (similar to the U.S. military). The thinking goes: A joint European force would allow the E.U. to unilaterally defend its interests, decrease reliance on American military might, and strengthen NATO as a whole. As supporters have argued, Europe is currently a vegetarian in a world full of carnivores and a unified defense force would give Europe the necessary jump it needs to fully compete.

The Messy Reality

While Pesco has gained momentum within Brussels, it will continue to face an uphill battle before any unified European force would be seen as a serious force to be reckoned with.

One significant hurdle for Pesco is political: How would nations prioritize their commitments to NATO or Pesco? As mentioned, NATO remains the preeminent military organization for the West and has played that role for decades. The creation of an autonomous, self-sufficient European military would necessarily require hard decisions of funding. It is not hard to imagine a situation where a nation must decide whether it will prioritize making weapons that fit NATO’s security needs or Europe’s specific security needs. This situation ends with either significant redundancies in capability for NATO (if the country prioritized  Pesco) or decreased capability for a European military (if NATO were prioritized). Given this, it is understandable why the United States would be wary of any joint European military — its funding would come at the expense of NATO’s (and by extension decrease American power).

A second hurdle for Pesco would be both logistic and political: Determining which countries would receive the juicy defense contracts. One of the greatest problems currently facing NATO is a lack of interoperability, and for a joint European defense force, the problem would remain. To tackle the problem, Brussels would have to determine which weapons to prioritize and which nations to receive the significant defense contracts. Of course, Pesco interoperability likely also would have to be interoperable with NATO equipment. Given that these arms manufacturers supply good jobs and heavily lobby their governments, the potential for a political tempest is real. Further, these decisions would only be made harder due to a current inability to mass produce arms for a legitimate military force. These hurdles represent the difficult decisions that would have to be made before any autonomous European defense force could be created.

The Bear to the East 

While Pesco has recently gained momentum because of increased Russian aggression and the entrance of NATO skepticism in American political discourse, one obstacle to a fully functioning Pesco is Russia itself. Russia will view any increased European defense capability as a direct threat to itself, sphere of influence, and interests. While it’s unclear what tangible actions Russia would take to respond to substantive Pesco developments, actions to hinder its development and an aggressive military posture would be an almost guaranteed response.

Looking Forward

There is certainly a legitimate case to be made for Pesco and a resurgence of European strategic autonomy. The world of 2018 looks vastly different than the one in 1948, with different actors, interests, and capabilities. But, like any large policy initiative, Pesco faces resistance from nearly every direction: NATO, Russia, Brexit, general anti-EU sentiment, various interest groups, and, not to mention, the political capital required to bring about such reforms.

This is not to say Pesco is a lost cause. In fact, quite the contrary: Europe has awakened to the reality that it can no longer sleepwalk through important security dialogues where its interests are not fully represented. Further, Europe recognizes that the security threats its faces today are the most serious it has faced since the end of the Cold War. These new threats warrant new responses. And while it’s unlikely that a full fledged Pesco will be part of Europe’s new response in the short term, greater collaboration and integration remains likely.