This article offers a challenge, in the form of an illustrative case study, to the notion that Finland's NATO membership is a radical reversal in security policy. With the use of shelter theory, it examines how Finland (as a small state), beginning in the Cold War, has actively sought to achieve political, economic and societal shelter from Western organizations. However, due to geopolitical restraints, the country has at various times been unable to fully adopt preferred shelter arrangements, especially within the military security sphere. The analysis indicates that the institutionalisation of Finland's shelter strategy has often been a tedious, diplomatic quest to integrate with the West, contingent upon opportunistically taking advantage of external ‘critical junctures’ to solidify its own interests. The article posits that Finland's pursuit of Western economic and societal shelter during the Cold War transformed into further Western political shelter‐seeking in its aftermath and, finally, membership of NATO in 2023. The case of Finland indicates that shelter theory captures the foreign policy strategy of a small neutral/nonaligned state. Nevertheless, our specific case also indicates that the theory ought to take a closer look at four features regarding relations between small and large states, that is how an agressive neighbour can restrict a small state's foreign policy choices, how economic and societal shelter relations may precede political shelter relations (or vice versa), the role of critical junctures within shelter theory, and, finally, how a history of cooperation may be transitioned into full‐fledged shelter.