German soldiers stand on the tarmac with their backpacks facing a Transall military supply aircraft at the NATO  air base in Hohn, Germany, in September 2014. (Daniel Reinhardt/European Pressphoto Agency)

When President Trump says America's European allies should boost their militaries, he means they should increase their respective domestic defense budgets.

But that's not how Europeans understand the idea of boosting military capability — a difference that could shape the transatlantic defense debate significantly over the next years. European defense officials consider something else far more important than increasing spending: making their armies more efficient.

European officials will point out that some nations with high military spending, like Greece, nevertheless lag behind when it comes to the operational capabilities of their armies. And multinational military units, financed by several countries, are increasingly seen as a way to increase the efficiency of Europe's militaries at low cost.

A Dutch-German multinational brigade has already existed for decades. Ukraine, Lithuania and Poland recently established a joint army unit, while Norway, Romania and the Czech Republic have announced plans to deep military cooperation. And just this week, Germany and France announced plans to establish a joint fleet of 12 military transport planes. All of this indicates how European militaries could change over the next years.

Joint military units are supposed to solve a problem that has worried defense officials for years. By financing 28 different national armies, they say, E.U. member states waste too much money on investments that could theoretically be shared among countries. For example, France and Germany might be better off sharing 15 new helicopters rather than each fielding 10 obsolete ones.

Supporters of joint units say the end goal is not to create one unified European army. “There won't be a European Army anytime soon, if ever,” said Marcel Dirsus, a German security politics scholar. Foreign and defense policy are at the core of national sovereignty [and] European states often disagree vehemently when it comes to the use of force. The Iraq War is an obvious example. What would a European Army do if some countries want to use force and others do not?”


A U.S. soldier watches as a statue of Iraq's President Saddam Hussein falls in central Baghdad in April 2003. (Goran Tomasevic/Reuters)

The war in Iraq strengthened disarmament supporters in Europe, but more recent conflicts have weakened their influence againThe NATO air campaign in Libya in 2011 and France's intervention in Mali in 2013 made Europeans realize the extent to which they rely on private contractors or the air forces of other countries, especially the United States.

“It was a wake up call which resulted in an agreement that more should be done on a European level,” said Martin Michelot, a French defense expert with the German Marshall Fund.

Britain's decision to leave the European Union also helped those who have long demanded stronger military collaboration in Europe. The United Kingdom had opposed closer military ties over fears it would lose control of its own army, which is one of Europe's largest. Following the Brexit vote, the European Union announced the establishment of a joint center that coordinates European military training missions in Africa and elsewhere.

But will more efficient European militaries satisfy President Trump? Maybe not, and some countries — especially in Eastern Europe — argue the continent should prepare for a scenario in which many nations will be forced to almost double their defense spending in less than a decade. All NATO members have committed to spend 2 percent of their respective GDPs on defense by 2024, but it is likely that many nations won't be able to meet that target.

Even if they were to increase their budgets only slightly, major revisions in the European defense industry would be necessary. European defense companies are not equipped to suddenly increase production of tanks, helicopters or planes, meaning that American companies would likely benefit most from any increases in European defense spending.