Why No Suicide Attacks In US?

USA Today asks why haven't there been any suicide attacks in America since the Sep 11 attacks, when such attacks are proceeding apace elsewhere. The government says suicide attacks on the American homeland are inevitable. There are many theories why they haven't come to pass:

American Muslims are better integrated and less radical than Muslims in Europe and the Middle East. American Muslims think of themselves as Americans first while foreign Muslims think of themselves as Muslims first. That means that there are much fewer volunteers for suicide missions and very little infrastructure to support such attacks. In fact, the American Muslim community has thwarted some suicide attacks by informing the authorities.

Al Qaeda is pretty much dead now, its last few members expending the bulk of their energy on surviving, pausing only to make the occassional videotaped empty threat. On the other hand, some think Al Qaeda is biding its time, slowly preparing another spectacular attack. Meanwhile, the war in Iraq is sucking up the supply of suicide bombers, who are mostly Saudis.

The US is better defended now, having bunkered up the likely targets and awakened to the terror threat. The last theory is that we have just been lucky.