The London bombings are likely part of a wider al Qaeda summer offensive.

There are a number of interesting observations here. Of course, the commentator is partisan, so take with salt. I presume this is mostly a show for the mideast rather then something intended to influence the west. However, we are moving in to the period of time where it is in the interest of the coalition to reduce their presence in Iraq, and Al'Q may attempt to force the west to stay or take credit for withdrawls.

James S. Robbins on 7/7 London Attacks on National Review Online