In a clear response to a Russian intelligence service arson attack on a London factory, the United Kingdom has said that Ukraine can use British weapons to strike targets inside Russia.

This bears particular note in relation to the U.K.’s Storm Shadow cruise missile, a number of which Ukraine possesses. Ukraine has previously used these missiles to great effect in targeting Russian naval forces in Crimea. But assuming its aircraft can survive Russian air defenses along Ukraine’s northeastern border, Ukraine will now be able to use Storm Shadow to reach targets in and around the Russian cities of Voronezh Kursk, Bryansk, and Orol. This will allow Ukraine to hold Russian command and logistics elements at far greater risk, complicating Russian ambitions to seize Ukraine’s eastern bastion city of Kharkiv.