Former US President Donald Trump has once again sent shockwaves through the transatlantic alliance, declaring that NATO allies "need us much more than we need them." This stark warning, delivered to reporters aboard Air Force One, has reignited a profound and difficult debate across European capitals: what would become of the world's most powerful military pact without the United States as its cornerstone?
The American Backbone and the 5% Pledge
The United States has long been the undisputed pillar of NATO. In 2025, the combined military expenditure of all alliance members reached a staggering approximately $1.5 trillion. Crucially, the US contribution alone accounted for over $900 billion of that total. The disparity in commitment has been a persistent point of contention, particularly for Mr. Trump, who long argued that the previous target of 2% of GDP on defence was insufficient.
This pressure culminated at last year's NATO Summit, where members agreed to a new, more ambitious goal: raising defence spending to 5% of GDP by 2035. In 2024, the US itself spent around 3.38% of its GDP on defence, a figure surpassed within the alliance only by Estonia (3.43%) and Poland, which led the way with 4.12%.
Raw Power vs. Strategic Enablers
On paper, a European-led NATO would still command formidable resources. Excluding the United States, the remaining 31 members control over one million active troops, with Turkey fielding the largest force at more than 355,000 personnel, followed by France, Germany, Poland, Italy, and the United Kingdom.
The collective hardware also appears robust. NATO as a whole dominates Russia in conventional forces, with around 3.5 million active personnel versus Russia's 1.32 million, over 22,000 aircraft to Russia's 4,292, and 1,143 military ships compared to 400. European nations also possess advanced capabilities: the UK operates two modern aircraft carriers, while France and the UK maintain independent nuclear deterrents. The combined nuclear arsenal of the US, UK, and France totals 5,692 warheads, slightly above Russia's estimated 5,600.
However, military experts warn that raw numbers are misleading. According to analysts like retired US Major General Gordon 'Skip' Davis, Europe's critical shortfall is not in manpower or platforms, but in the "strategic enablers" essential for modern warfare. These include integrated intelligence, surveillance, and reconnaissance (ISR), strategic airlift, space assets, cyber capabilities, and long-range precision strike systems—areas where Europe remains heavily reliant on Washington.
"What the US brings is capabilities like strategic command and control systems and ISR assets," Davis cautioned, stating that without them, European forces would struggle to sustain a prolonged, high-intensity conflict.
Command Structures and the Ukraine Litmus Test
The institutional dependency runs deep. NATO's most senior operational commands, including the Supreme Allied Commander Europe (SACEUR), are all led by US officers. "I don't think that NATO could operate without US commanders and staff. That would be extremely difficult," Davis admitted.
The war in Ukraine has acted as a stark stress test, exposing severe European shortages in ammunition stockpiles and industrial capacity. The EU failed to meet its target of supplying Ukraine with one million artillery shells by spring 2024. Meanwhile, the US doubled its monthly production of 155mm shells, and American-supplied systems like HIMARS and Patriot air defences have been central to Ukraine's war effort.
The brief pause in US aid at the start of March 2025 raised acute doubts over whether European allies could compensate if American support were withdrawn permanently. With Russia reportedly producing around three million artillery shells annually, the industrial gap is a pressing concern.
Trump's comments were made while he reiterated his controversial interest in acquiring Greenland, framing it as a national security necessity to prevent Russian or Chinese influence. He dismissed the island's current defences as "two dogsleds" compared to Russian military presence. When asked if purchasing Greenland could compromise NATO, he replied, "Maybe NATO would be upset if I did it… I like NATO. I just wonder whether or not if needed NATO would they be there for us? I'm not sure they would."
This has revived deep-seated fears that America's commitment to NATO's Article 5 collective defence clause—invoked only once after the 9/11 attacks—is no longer guaranteed. In response, NATO Secretary General Mark Rutte stated on Monday that the alliance is actively "working on the next steps" to bolster Arctic security, highlighting the ongoing geopolitical shifts that make the question of European self-reliance more urgent than ever.
