There have been plenty of attacks. They just occur in the Middle East. Bin Laden and the other Islamic insurgents wnat to break the military strength of the United States like they did the USSR. If they succeed, the US will no longer be ABLE to occupy Muslim countries, support Israel or apostate regimes or carry out what Islamists see as a war on Islam.
People need to realize that Islamists are not insane terrorists bent on world domination or the destruction of the Western Wrold, and they do not hate America because we are free. They are insurgents fighting against an imperial power (the US is an imperial power, but I am not using that term to criticize the US) for a few very specific goals.
If you want to understand Islamists, you should read Imperial Hubris by Michael Scheuer. Scheuer is the former head of the CIA's Bin Laden unit and has spent over twenty years working in the intelligence community, focusing on Islamists. He is an expert on the subject. The book is very enlightening. I cannot recommend it highly enough.