Centuries of taking our land

Al-Zawahiri taking responsibility for the London attacks:

'I talk to you today about the holy attack on London, which came as a slap in the face of the arrogant British crusaders,' he said, in Arabic.

'Now you can taste a sip from the glass Muslims have drunk from for centuries. This attack adds to the attacks before in Washington, New York and Madrid. We have moved the battle to the land of the enemy after they battled us in our land for so long.

'After centuries of invading our land and occupying it ... this is for you to taste some of what you have made us taste before.'
CNN.com - U.S., UK investigate 'bomber tape'

Very 'clash of civilisations'. What can you do about an ideology that is seeking retribution for 'centuries of invading our land'.