There are some things you just don't do. It is not wise at all, to poke a Mama Bear, with a stick, while she's trying to feed her newly born cubs.
Like wise to claim responsibility for one of the greatest man made tragedies, that one of the strongest nations on the planet has ever suffered, is fool hardy.
The example was set after Japan destroyed Pearl Harbor. The response was, two A-Bombs, and the total devastation of Japan's economy.
You look long enough and hard enough and you can find a needle in a Hay Stack.
So the answer to the question is [SUICIDE]. When OBL made the decision to attack the World Trade Center, he placed a gun to his own head and pulled the trigger. Just took the bullet longer to travel down the barrel.