STOCKHOLM - Today, SIPRI has released a paper that investigates the significance of nuclear weapons for umbrella states, challenging the role of nuclear weapons in current nuclear strategies.

This paper examines the role of nuclear weapons in military alliances, focusing on the perspectives of the so-called umbrella states—that is, allied states that do not have their own nuclear weapons but are part of the ‘extended nuclear deterrence arrangements’ of a nuclear-armed patron. After analysing allied security thinking and highlighting the underlying assumptions about nuclear deterrence, the paper subjects some of those assumptions to critical scrutiny.

Taking into account regional military balances and escalation risks related to nuclear deterrence, it challenges the perceived security benefits of forward-deployed non-strategic weapons, continued support for allied nuclear doctrines based on readiness for the first use of nuclear weapons, and the assumed inevitability of nuclear second strike that underlies the practices of nuclear assurance.

The goal is to open discussion on the development of a more measured approach to deterrence that would allow for minimizing the role of nuclear weapons in military alliances.

About the author

Tytti Erästö (Finland) is a Senior Researcher in the SIPRI Weapons of Mass Destruction Programme, focusing on nuclear disarmament and non-proliferation issues.

To Download the full paper, visit: https://www.sipri.org/sites/default/files/2024-06/2024_1_nuclear_weapons_in_military_alliances.pdf