Under the standards of international law, al Qa'ida is too puny to qualify as an enemy to be at war with. It is unable to carry out military operations.

Thus, the US should stop treating this as a war.

Obama misused the word "decimated", which means to kill 1/10 of the soldiers in a military unit. (It was a Roman punishment for mutiny.) Al Qa'ida has been far more than decimated.