U.S.-Ukraine Intelligence Sharing: A Conversation with Calder Walton

Belfer at the Munich Security Conference

Belfer Center experts convened at the Munich Security Conference in February 2025 to contribute to the world's critical international security issues of the day.

Explore our work including the launch of a landmark report on the transatlantic relationship; a Belfer Center-sponsored side event on the developing adversarial alignment between Iran, North Korea, China and Russia; and watch media interviews live from the conference here.

Face-Off: The U.S. vs China

Face-Off is a podcast about how China and the United States, once friends, are now foes.

Hosted by Jane Perlez, Pulitzer-prize winning journalist, former New York Times Beijing Bureau Chief and Belfer Center Fellow, and Professor Rana Mitter, ST Lee Chair in US-Asia Relations.

Now in its second season, episodes are available every Tuesday on Spotify, Apple Podcasts, and more.

Putin's Preventive War

The 2022 Russian invasion of Ukraine matches the logic of preventive war, when states fear the consequences of a shifting balance of military power and strike to forestall it.

In the latest issue of International Security, Barry R. Posen argues that Vladimir Putin likely viewed Russia’s strategic situation through a preventive war frame--that increasing U.S. and NATO military cooperation with Ukraine likely convinced Putin that he did not have much time to forestall Ukraine’s NATO membership, which would shift the balance of power against Russia.

Belfer Center Director Meghan O'Sullivan discusses strategic priorities for the coming decades