I think the question (Will Europe ever fully partner with the U.S.—or will the European Union and NATO continue to downplay the necessity of military readiness?) is lagging the reality of European acknowledgement of their military shortfalls. Europeans are no longer downplaying the necessity of military readiness.
Russia’s 2014 capture of Crimea and invasion of Ukraine’s contiguous territory shocked Europeans into the realization that they had for too long pretended the end of the Cold War ended the threats requiring military responses. Defense spending in most European countries started increasing in the immediate aftermath of Russia’s aggression. NATO countries also agreed to the goal of 2% GDP on defense spending by 2025 at the Wales summit of 2014 in response to Russian aggression. NATO Secretary General Jens Stoltenberg said on October 2 at the meeting of NATO Chiefs of Defense, all NATO countries have increased their defense spending, an average of more than 5% since 2014. Russia’s continued malevolent behavior, seeking to affect election outcomes in the West, poisoning British citizens on British territory, has cemented attitudes in Europe that Russia is a predator and a threat to the West.
The other shock that has energized European efforts to increase military readiness has been the election of President Trump, which gave both negative and positive impetus. Negative in the form of the President of the United States denigrating the value of allies and alliances—for example, retorting to Canadian Prime Minister Justin Trudeau’s appeal against national security grounds for trade sanctions with “it’s useless to make tear-jerking speeches about Canadian soldiers fighting alongside the US in the war if he then puts very high tariffs on dairy products.”1
Concern about the reliability of U.S. security guarantees has also encouraged cooperation among U.S. allies in the EU and other realms. The EU’s Permanent Structured Cooperation is admittedly another bureaucratic exercise, but it does have the potential to make better use of existing resources, especially for the smaller European countries. French President Macron has also gained support for a European operational force outside EU structures; the excellent performance of French forces in Mali and elsewhere are providing a framework other European nations can participate in and emulate.
Moreover, fear of a post-American international order has scared American allies in both Europe and Asia to cooperate to try and uphold the order without American leadership. Europeans are beginning to acknowledge former Norwegian Foreign Minister Espen Barth Eide’s warning that “China is not just rising for the United States, but also for Europe.” France and Britain are jointly conducting freedom of navigation exercises in the South China Sea, France and Australia are likewise conducting joint military exercises.
President Trump’s election was also a positive effect on efforts to increase military readiness in the creative activism of Secretary of Defense Jim Mattis to devise cooperative projects like NATO’s “four thirties” that overcome operational shortfalls. Designed to demonstrate practical progress, the 430s initiative commits NATO allies to the standard of producing thirty battalions, thirty squadrons, and thirty ships for combat within thirty days. NATO allies committed to this at the Brussels summit in June 2018—although President Trump chose to make the summit divisive. He could equally have celebrated the progress in increasing spending and readiness.
So Europe is doing better than the question suggests, partly because of American leadership, partly because of its absence.