Here is a thought provoking article that touches on why we didn't start the War on Terror sooner.
Powerful institutional forces in the Pentagon CIA and State Dept. kept the thing from getting elevated to the status of war. Terrorist control was approached from a law enforcement rather than a millitary threat.
Generals did not want the special forces to get involved in little wars (legacy of VietNam) and many in the military thought that fighting "bandits" was beneath a military intended to fight WW3.
Not stated in the article is another possible reason. The US Millitary as a whole actuallytakes its seperation from law enforcement more seriously than is often supposed. The USCG would not exist were it not for the fact that we have an actual law enforcement role. Bouys could be handled by the Army and SAR by the other 3 services. The USCG fills an important nich that the Navy DOES NOT WANT TO FILL. This is not a slap at the Navy, it is in fact comforting that they take their constitutional duties seriously enough to not want to get involved in law enforcement. The aformentioned declaration of terrorism as a law enforcement problem would have set off alarm bells amongst flag officers who, especially since the warnings of Eisenhower and the ddebacle at Waco have been suspicious of any attempt to bring in Millitary units to do LE.
Note that when the Navy was tasked with drug patrols, they requested CG elements be on board to do the actual arrests ect.
By making terrorism a Law Enforcement problem the millitary would have had a real reason not to get involved.
Most astonishing is the fact that Clinton actually asked for an agressive stance using special forces but was talked out of it by risk adverse flag officers and wonks.
READ THE WHOLE THING
This is big.
It is widely known that Bush had asked for a set of plans to be drawn up after he took office speciffically to deal with AlQuaeda and the Afganistan problem he ran into the same institutional reluctance to deal with it as a millitary problem. It seems that only 9/11 took the gloves off.
Now, it seems that the pentagon types and wonks are again looking at the special forces as pariahs. This needs to be stopped, fixed and the pecetime generals and admirals need to be put out to pasture.