The Chicago Way
I'm not advocating simple, mindless violence with my title. I'm advocating devious, subtle violence with an extra twist of the knife. So Jihadist Local #236 claims responsibility for detonating office workers and bus riders because of Britain's soldiers in Iraq? Very well. Let the number of British soldiers in Iraq be increased by the same number of dead and wounded from the attack, and should another take place, again take the number of dead and wounded -- and multiply it by five. We'd do the same, of course, if we are attacked. And make sure to tell Al Jazeera and anybody else who will listen that's why those extra soldiers are there.
(If I was Evil Overlord I would not allow any news media to broadcast the "claim of responsibility" until the Jihadist Local #236 had been rounded up, paraded through the streets as an example and a warning, and then sent to the salt mines. Remove the rewards for blowing up innocent civilians, you idiot journalists!)