While Trump's tough stance successfully induces allies to increase defense spending, this gain in capability is offset by a catastrophic loss of trust. An alliance's strength is based on both capability and will. By making the U.S. commitment (like Article 5) conditional and unreliable, overall deterrence against adversaries like Russia is weakened, making war more likely.
Trump's treatment of arms sales to Taiwan as a 'bargaining chip' and his dismissive comments about old commitments could be the tipping point for Asian allies. Just as the Greenland threat awakened Europe, Trump's transactional approach to Taiwan's security signals to Japan, South Korea, and Australia that their own long-standing treaties may also be considered negotiable.
Contrary to the belief that Gulf states always wanted a hardline US policy on Iran, their perspective shifted after 2019. When Iran attacked Saudi and UAE assets and the Trump administration failed to respond, they realized the US was an unreliable defender. This prompted them to make their own peace with Iran, a policy directly undermined by the recent US-led war.
The reluctance of U.S. allies to develop a 'Plan B' is not from ignorance but from the sheer difficulty of the alternative. For 80 years, the U.S. security guarantee was a 'good deal' that allowed allies to focus on economic growth. Accepting its demise means undertaking painful, costly, and risky actions like massive defense buildups and nuclearization, a conclusion they would rather avoid.
NATO's integrity is bifurcated. Its formal components—the military structure, institutions, and treaty—remain intact. However, its core function as a deterrent has been severely damaged because the US President has made the Article 5 commitment conditional. This undermines the perceived 'will' to defend allies, which is what truly deters adversaries like Russia.
European allies have successfully stepped up to provide Ukraine with military and financial support, replacing diminished U.S. contributions. However, they cannot replicate the unique American role as the central 'convener' of the alliance. The U.S. remains indispensable for pulling allies together to make high-level strategic decisions, such as those concerning war termination.
The recent war with Iran demonstrates the collapse of the traditional 'continuum of conflict.' It showed that future wars will not be exclusively low-end or high-end. Instead, they will feature a diverse array of capabilities used in parallel, from soft-target drone attacks and cyber operations to conventional F-35 strikes and the deployment of carrier strike groups.
European allies only began seriously developing a 'Plan B' after President Trump threatened to seize Greenland. While threats to NATO and trade were concerning, the idea of using force against a NATO ally to take its territory was a bridge too far, shattering any remaining illusions and prompting concrete pushback like military exercises and counter-tariffs.
Unlike Europeans who have NATO and native nuclear powers as a potential fallback, major Asian allies like Japan and South Korea feel they have no viable alternative to the U.S. security guarantee. This perceived lack of options forces them into a strategy of accommodation and appeasement toward a transactional Trump administration, hoping to simply endure the term.