On Tuesday, U.K. Prime Minister Keir Starmer hailed the possibility of NATO-backed security guarantees as a “breakthrough,” noting that the U.S. was now working “at pace” with 30 or so other countries, which he called a “coalition of the willing,” to help Ukraine.

NATO military leaders, including the U.S., are working to put together a strategy that would protect Ukraine if Russia breaks a peace deal. Charlie D'Agata has the latest.