The perpetrators of today’s attacks are intent on destroying human life. The terrorists will not succeed.

Today’s bombings will not weaken in any way our resolve to uphold the most deeply-held principles of our societies and to defeat those who would impose their fanaticism and extremism on all of us.

We shall prevail and they shall not.
– British Prime Minister Tony Blair

Never give in — never, never, never, never, in nothing great or small, large or petty, never give in except to convictions of honour and good sense. Never yield to force; never yield to the apparently overwhelming might of the enemy.
–Sir Winston Churchill

Update: A letter to the terrorists, from London (via Michael Totten)