Accusations of sabotage have been made after a Chinese merchant ship cut through two important undersea cables in the Baltic Sea. Eight of the nine states in the Baltic are members of Nato but Russia has access to the sea from St Petersburg and for its Kaliningrad exclave.

With previous incidents of damage to underwater pipelines and cables, there is concern that the security of critical underwater infrastructure is at risk from ‘grey zone’ activities - damaging but deniable incidents below the level of outright war.

David Baker hears how countries’ security is threatened by incidents like these. The pipelines that were cut ran between Finland and Germany and Sweden and Lithuania. He asks who can intervene to protect these assets in the Baltic. Can Nato respond?

Our experts this week are: Elizabeth Braw, senior fellow at the Atlantic Council Scowcroft Centre for Strategy and Security, and the author of an upcoming book called The Undersea War; Helga Kalm, director of the Lennart Meri Conference in Tallinn, Estonia; Marion Messmer, senior research fellow in the International Security Programme at Chatham House; Tormod Heier, professor at the National Defence University College in Oslo, Norway and a former officer in the Norwegian Intelligence Service.

Presenter: David Baker Producer: Philip Reevell Researcher: Katie Morgan Editor: Tara McDermott Sound engineer: Craig Boardman

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