MADRID — As the United States and the European Union size each other up for defense cooperation, a number of technical and philosophical obstacles continue to hamper substantial progress.

At issue is how both sides of the Atlantic can bridge the opposing poles of competition and cooperation as they seek to connect their defense industries in search of better capabilities for all, according to Jed Royal, deputy director of the U.S. Defense Security Cooperation Agency.

“We need to talk increasingly about a trans-Atlantic industrial base,” he said during a panel discussion at the FEINDEF international defense exhibit. While there are lots of political decisions still in play toward that end, a focus on partnerships would eventually make it so, he said.

Still, the devil is in the details. Working on European defense issues through channels other than NATO is in many ways new for Washington. And the American reflex of using its outsized industrial influence in the alliance is met by a European bloc eager to sharpen its own sword.

For example, various administrative arrangements with the U.S. government, as they are known in EU parlance, have yet to come to fruition. The bureaucratic-sounding deals are essential in defining the scope and authorities for any activity member states extend to outsiders.

Such an agreement is still elusive, for example, in a program aimed at improving “military mobility” in Europe, a reference to easing the cross-border flow of hardware and troops in the event of a crisis. A project under the EU’s Permanent Structured Cooperation, or PESCO, umbrella was opened to U.S. participation earlier this year, to great fanfare, but unfinished negotiations over an administrative pact continue to sideline the Pentagon.

“The United States is very pleased to be given permission to work within the PESCO military mobility project. It’s an excellent start, and we’re very grateful for that opportunity,” Royal said during the panel discussion. But “we think that the lack of an administrative arrangement right now unnecessarily hinders our ability to cooperate.”

Such is the nature of the U.S.-EU defense relationship so far: Amicability abounds, but common ground remains elusive behind a slate of technicalities.

There is also the question of whether a common, trans-Atlantic pool of defense companies is even desirable. Thierry Carlier, the director of international development at the French military acquisition office DGA flagged “sovereignty” and the need to prevent “dependency” as key features of any emerging defense-industrial agenda.

EU officials have been worried an overly enthusiastic embrace of the U.S. defense contractor ecosystem, which feeds on a $700 billion national budget, could make quick work of an industrial landscape on the continent struggling to streamline itself while remaining equitable for all member nations.

France welcomes negotiations between the European Defence Agency and the United States on an administrative agreement, Carlier said. “We expect lots of positive outcomes.”

At the same time, he suggested a greater focus on interoperability could help bring together the two continents where a focus on cooperative programs that risk falling short of national requirements cannot.

“If we travel a bit into the future — not that far — there could be a race between U.S. sixth-gen fighters with their loyal wingmen and the French-German-Spanish new-generation fighters with their remote carriers,” Carlier said, with a nod to the trinational Future Combat Air System.

Bridging those interoperability gaps should be a priority, he argued, with NATO as a key player in harmonizing the relevant links and standards.

“I believe we can share more, in terms of interoperability layers and expanding out cooperation to new technologies to a much bigger extent than we have in the past,” Carlier said.

In the end, Royal said, the amount of political will on both sides of the Atlantic will be critical in forging a U.S.-EU defense relationship. “We often think of political will when it comes to the moment of the use of force,” he said. “But we also need to be thinking about preparing and organizing ourselves for the use of force.”

The industrial base part, he argued, is part of that calculus.

Sebastian Sprenger is associate editor for Europe at Defense News, reporting on the state of the defense market in the region, and on U.S.-Europe cooperation and multi-national investments in defense and global security. Previously he served as managing editor for Defense News. He is based in Cologne, Germany.