NATO with out united states , cost analysis

Defence affairs (IISS)

A new IISS report assesses the financial costs and defence industrial requirements for a European NATO to defend against a future Russian threat if the United States were to withdraw from NATO. It finds that directly replacing key parts of the US contribution would amount to approximately USD1 trillion.

The IISS has conducted an independent, open-source assessment of the financial costs and defence industrial requirements for NATO-Europe to defend against a future Russian threat without the United States. Russia’s war of aggression against Ukraine, its hybrid war against European states, and demands by the Trump administration for European defence autonomy make it imperative for European decision-makers to consider the military, financial and defence industrial investments needed to reduce dependencies on the US and, in extremis, to prepare for a NATO without any US role.

The objective of the study is to inform European policymakers’ thinking about the military, financial and defence industrial implications of closing key military gaps.

To inform the European defence policy debate, the study assumes that by mid-2025 the war in Ukraine has ended with a ceasefire agreement and that the US government has indicated that it will begin the process of withdrawing from NATO. Declaring its need to prioritise the Indo-Pacific theatre, the US also commences to remove equipment, stocks, supplies and military personnel from Europe. The IISS does not assume this scenario to be inevitable, but it is a helpful construct to clarify policy and capability decisions for European governments today.

Against this background, the study first assesses Russia’s ability to reconstitute its forces after the fighting in Ukraine ends. Our assessment is that challenges notwithstanding, Russia could be in a position to pose a significant military challenge to NATO allies, particularly the Baltic states, as early as 2027. By then, Russia’s ground forces could mirror its February 2022 active equipment holdings through a combination of refurbishment and the production of new systems. Moreover, its air and maritime forces have been largely unaffected by the war.

Consequently, were US forces to disengage from the European theatre from mid-2025, Europe’s window of vulnerability would open quickly. Not only would European allies need to replace major US military platforms and manpower – the latter estimated at 128,000 troops – but also address shortfalls in space and all-domain intelligence, surveillance and reconnaissance assets. They would also need to replace the significant US contribution to NATO’s command and control arrangements and fill many senior military positions in NATO organisations currently occupied by US personnel.

To replace the currently assumed US conventional capabilities assigned to the Euro-Atlantic theatre, European states would need to invest significant resources on top of already existing plans to boost military capacity. The IISS estimates that taking into consideration one-off procurement costs and assuming a 25-year lifecycle, these costs would amount to approximately USD1 trillion.

Unlocking such funding would be possible but would come with considerable challenges for many European states. More radical approaches to defence investment and defence spending levels closer to Cold War levels – where spending ‘routinely averaged’ over 3% – would be required. On the positive side, several European countries and the European Union have started to pave the way for increased defence spending and a better defence investment environment. But whether the political will to deliver the spending levels necessary will be forthcoming across European nations remains to be seen given the limited fiscal space for many governments.

In addition, European allies face defence industrial challenges. While procurement orders have picked up pace in the land domain, there has been less urgency in the naval and much of the aerospace sector, with little additional investment in more production capacity. This is problematic since the large-scale provision of air and maritime platforms would be a key requirement if Europe had to replace the US military contribution in these domains. Additional defence industrial challenges relate to contracts, financing, workforce shortages, regulation and security of supply.