We're hearing from the Kremlin, which has branded Lord Cameron's comments about Ukraine striking inside Russia "dangerous and worrying".
Spokesman Dmitry Peskov said Ukraine can use British-supplied weapons to target areas in the country if it wants, but the decision would be a "direct escalation".
On a visit to Kyiv yesterday, Lord Cameron said Ukraine has the right to strike targets inside Russia "just as [Moscow] is striking inside Ukraine".
He said he could understand why Ukraine feels the need to make sure it is defending itself and that it was its decision how it would use British-supplied weapons.
Hitting back, Mr Peskov said Lord Cameron's comments could "imperil the entire system of European security architecture".
somehow the threats from a country thats only taken 10% of Ukraine in 2 years may not seem to frighten 1