'Cowardly attack'? If it IS a suicide attack, you can't call them cowardly, unless you change the meaning of the word. Let's not fall into the trap of attributing only vices to our enemies (and by corollary, only virtues to ourselves).

Vicious, murderous, fanatical, destructive of their own cause, yes. Let's make sure they don't win by provoking attacks on good honest British Muslims.