Whose incompetence? There were a number of terrorist attacks over the period from 1976 (Carter Administration) through the 1990s (Clinton Administration). Clinton had the opportunity to take out Bin Laden at least once, perhaps twice, but chose not to because we didn't have a 'smoking gun' sufficient to justify - that's an arguable case. 9/11 planning by Bin Laden began in at least 1999, perhaps 1998 - I don't recall. So if you're saying it was Bush incompetence, you're just uninformed. The fact is that Bin Laden (who was a big part of the "Mujahadeen" that we financed to fight the Soviets in Afghanistan in the 1970s) dedicated his life to killing infidels at that time if not before.
Afghanistan was not such a bad place prior to the Soviet invasion and removal of the king (not necessarily in that order). I have friends and relatives who worked there and visited there in the early 1970s. But the Russians have wanted a direct route to a warm water port for centuries, and have tried various methods multiple times including overthrowing governments. See also the "Great Game" of the 1800s between Russia, Britain, and China mostly.
It's quite reasonable actually to go back much farther, to the Jefferson Administration, in 1801-1809. See the Tripolitan War or Barbary Coast War, 1801-1815. US merchant shipping in the Mediterranean was being hampered by pirates out of Tripoli (present day Libya), who were seizing the ships and holding the crews and passengers for ransom. For several years the US (like several European nations) was forced to pay as much as $1 million per year to protect our fleets. When the US Ambassador went to Tripoli to negotiate, and find out why they kept attacking, the sultan or whatever said, "Holy Kuran tells us to kill all infidels. The fact that we don't kill your people but only hold them for ransom is merely a sign of our exceeding mercy." This was the motivation for Jefferson to build up the Navy, I think create the Marines but I'm not sure about that, and go to war. This is the basis for the latter part of a line in the Marine Hymn, "From the Halls of Montezuma to the shores of Tripoli."
IOW, the western European and American nations have been dealing with murderous thugs from those areas since the birth of this country.