No they couldn't come sooner because the United States stopped a previous Al Qaeda attempt to hijack and crash 11 US airliners led by a man named Ramzi Yousef. And the attempt before that to topple the twin towers, in 1993, failed.
10,000+ illegal immigrants cross our border every day but somehow AQ members couldn't get in the country? And the attempt before that to topple the twin towers, in 1993, failed.
Wasn't Yousef the mastermind of the 93 attack?
And while the attack failed in its goal of toppling the towers, the attack was successful in that they were able to pull it off.
And I would like more information on Yousef being foiled in his attempt to hijack 11 airliners. Please provide.
In January of 1995. Nearly seven years prior to the 9/11 attacks. It should also be noted that the early plans for the 9/11 attacks were found on Yousef's computer that was seized after he set his apartment ablaze.
So they had the plans for the 9/11 attacks all that time, they just couldn't do anything with them for seven years. Which means they didn't have the means (money, jihadis, training) until 2001. That's fine if you believe that. I don't.