germany has attacked britain a great deal many times over the last two thousand years, including the premise of the shakspeare play hamlet and accounting for the fact that the british people today speak a dialect of german. also, world wars one and two.
the closest thing to a war between russia and the uk was the crimean war, which involved the uk attacking russia. rather, the uk and russia are historical allies when things get tough, and they usually align against the damn germans.
what's happening now - germany rebuilding it's army to fight an aggressive war in ukraine against russia - puts britain at imminent threat of danger from it's primary recent historical antagonist. for that reason, the british should be seeking to wrap this up like a cupcake at tea time.