Ben Barry
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.