This article is part five of a series examining the challenges confronting the NATO alliance. For over three decades, the United States has carried the largest share of NATO's military burden, while many European allies have spent less on defense than the U.S. desired. This imbalance persisted through the Cold War and various U.S. administrations, with significant increases in defense spending among NATO members only occurring recently, following Russia's 2022 invasion of Ukraine and pressure from President Donald Trump.
Defense analysts attribute the long-standing gap in spending to a combination of post-Cold War optimism, domestic political priorities, and the perception of security provided by the U.S. defense umbrella. Barry Posen, a political science professor at MIT, noted that during much of the post-Cold War period, European nations underinvested in defense due to low perceived threats and the belief that the U.S. would remain committed to their security.
After the Soviet Union's collapse, European governments redirected resources toward domestic priorities, resulting in a 22% decline in defense spending among European NATO members from 1992 to 1999. As defense budgets shrank, social welfare programs expanded, making military spending cuts politically challenging. Critics argued that American taxpayers were subsidizing European security, allowing allies to focus more on domestic issues.
This dynamic led to a 'moral hazard' problem, where the U.S. commitment to NATO allowed allies to underinvest in their militaries without facing immediate consequences. Over time, European militaries became increasingly reliant on American capabilities, including logistics and missile defense.
American frustration over burden sharing has been a recurring theme since NATO's inception. In 1953, President Dwight D. Eisenhower urged European allies to take on a larger share of defense costs. This concern continued through various administrations, culminating in a 2011 warning from then-War Secretary Robert Gates about the future of NATO if European nations did not increase their military investments.
Despite decades of warnings, the incentives for change remained limited, as the U.S. reaffirmed its commitment to NATO and maintained a significant military presence in Europe. The urgency of the issue increased following Russia's annexation of Crimea in 2014, leading NATO to establish a benchmark for member nations to spend at least 2% of GDP on defense. Although spending has gradually increased, progress has been uneven.
The cycle of burden-sharing disputes continued, with American officials urging allies to increase defense spending while European leaders made promises without significant changes. The situation shifted after Russia's aggressive actions and Trump's questioning of U.S. defense commitments to allies that did not meet spending targets.
At NATO's summit in The Hague, allies agreed to a new goal of spending 5% of GDP on defense by 2035, marking a significant increase from the previous 2% benchmark. This agreement reflects a consensus that the security environment has become more dangerous since the Cold War.
However, analysts caution that rebuilding military capabilities is complex and requires more than just increased budgets. Europe remains dependent on the U.S. for various military capabilities, and translating financial commitments into military readiness will take time. John Byrne of Concerned Veterans for America emphasized that while equipment can be purchased, command experience and leadership cannot be acquired instantly.
