In addition to the market instability instigated by the Trump administration‘s changing tariff policy, a corollary set of effects are occurring in international security. The full extent might only be observed over time, but US tariffs have the potential to create results that contradict Washington’s security goals.
President Donald Trump believes that he can be excessively aggressive, even churlish in his policies because other nations just cannot afford to dismiss the US. But his repeatedly changing tariff announcements put that belief under more pressure than ever. As commerce with the US increasingly becomes more complex, unpredictable, and costly, some nations – including major US allies – might perceive greater incentives to reconsider the degree of their security reliance on Washington.
The impact on global security is playing out in varying ways for European and Asian allies, two groups that have benefited from US security guarantees for eighty years. Both, however, are reconsidering how devoted this US administration is to their interests.
Europeans are experiencing confusion
Europeans were nervous about President Trump’s pledge to secure them before he was elected into office. Policies by his administration on NATO and the conflict in Ukraine further escalated their fears. The US search for peace talks with Russia, excluding European interests, has highlighted the US quest to withdraw its pledges on the continent as fast as possible.
That has led the leaders of Europe to take seriously Trump’s 2024 election platform: it is now anathema that European governments can somehow get along on lower defence spending and must carry the whole weight of protecting their continent.
European governments are already adopting a ‘buy European’ policy of procurement. That may be regarded as a foreign policy victory for President Trump: but the tariffs have now put a new economic case for a decoupling policy of some European security dependencies from Washington.
Few European governments have traditionally acquired weapons systems from the US due to its advanced technology and economies of scale. But all that may now be about to change. Portugal, Canada and other US allies are currently considering not buying the US-made F35 aircraft. Tariffs will also make it more expensive for US defence products, if only because US defence firms will have to pay more to import vital components from world markets.
And already European governments are embracing a ‘buy European’ strategy on procurement: an additional €150 billion EU rearmament fund would lock US companies out of competition for contracts. A decline of defense exports to Europe was certainly not something the Trump administration wanted. Nor was the development of a European defense industry that could eventually compete more successfully with the US on sales to other markets. That would be far beyond Trump’s current goal of Europe paying more for its own defense.
No matter how much the US may protest at being kept out of European procurement, the recent tariff volatility can only advance the argument for Europe to increase investment in its own defence industrial base, which has been struggling to offset deficiencies resulting from the supply of military hardware to Ukraine.
Asia and the Pacific region
In Asia the effects of tariffs uncertainty will be experienced differently. US security allies in Asia and the Pacific are not engaged in an ongoing regional armed conflict such as Ukraine. And there is no multi-party security agreement like NATO whose very existence is threatened by the Trump administration in the same manner. Rather, a series of discrete security relationships between the US and Asia-Pacific nations exist. The Trump administration is also more engaged in the region. While direct confrontation of Russian forces in Europe is entirely out of the question for the US, preventing China from expanding in the Pacific is an unmistakable strategic imperative.
But this will not be enough to fully assuage nerves among local allies. As in Europe, there is growing perception that the US cannot be trusted as a security ally in the same manner as in the past.
Asia-Pacific nations are faced with an adverse regional security situation, with China developing its military at speed while aligning with Russia and North Korea. And potential flashpoints for conflict are evident enough, from Taiwan to the Korean Peninsula and the South China Sea. Defence spending is growing accordingly.
Breaking the connection
The impact of Trump’s tariff measures has been that in certain quarters, US allies are being encouraged to unplug from their security dependence on Washington. There is now a compelling argument for more security cooperation between mid-tier US partners that bypasses or reduces US dependencies.
Trump can use his leverage to compel US partners to spend more on defence – but at a price. Now there is even more justification for greater security co-operation among small and medium US partners that gets around or diminishes US dependencies, eroding US leverage. Sales of US weapons systems would likely fall by kind, since other defence export nations become progressively stronger. None of these two consequences is liable to be welcomed by Trump.
Whichever way the strategic vision evolves in the next few years, European and Asian nations will likely never again make the same assumptions about the place of the US in their security frameworks even if they continue to be full members of their alliances and partnerships with the US.
