While core Al Qaida, the group that managed to destroy the World Trade Center on September 11, is decimated, Al Qaida is more a philosophy, a Way of Life dedicated to ending the West. In this sense, Al Qaida is a direct threat to our way of life, eternal vigilance is needed to find and stop the threat,\.
Overall while the organization has been weaken in recent years Al Qaida still poses a substantial threat to the United States, while we may have killed some of the main leaders in the organization there are many who were just as powerful that are still alive and still are planning against the United States.
As long as Al Qaida exists it will remain a direct threat to the United States. There have been no new missions statements coming out of Al Qaida stating that all has been forgiven with the West. This does not mean that they are still the same level of threat that they previously were or that they are currently the most pressing threat, but given the means and opportunity, Al Qaida would do further damage to the United States.
Direct threats to a country's sovereignty has never been an issue for the United States. What Al Qaida is asymmetrical threat and it will continue to be this as a third party actor for years to come. The United States helped build Al Qaida and made it a self recruiting self sustaining entity. The United States should not be surprised by the results of its work