I don't usually do this, but I wish to quote David French from NRO in its entirety because it is short and to the point.
Let’s make this simple, shall we?I hope one day our spent western culture musters enough manhood to actually go and stop these barbarians just so a future 'historian' can tell us how us awful Christians attacked the innocent muslims in a new crusade or something...
1. Al-Qaeda carried out the deadliest attack on American soil in American history and the most devastating foreign attack against an American city since the British occupied and burned Washington during the War of 1812.
2. ISIS is more brutal than al-Qaeda.
3. ISIS has more financial resources than al-Qaeda.
4. ISIS controls more territory — and possesses more firepower – than al-Qaeda.
5. ISIS has seized uranium in sufficient quantities to make a radiological weapon, a dirty bomb.
6. The leader of ISIS declared to his former American captors, “See you in New York,” and ISIS militants have pledged to raise the black flag of jihad over the White House.
In other words, ISIS is more capable in every way than the terrorists that hit America so hard on 9/11. Pinprick strikes weren’t enough to stop a much weaker Osama bin Laden. They will not be enough to stop a much stronger Abu Bakr al-Baghdadi.