Looking back over the decade, the first clear lesson is the critical importance of Mr. Bush's decision to consider the struggle with al Qaeda a war.

Defeating al Qaeda in Yemen cannot be achieved solely through the removal of its top leadership. Conditions in Yemen, even before the outbreak of the Arab Spring, are favorable for al Qaeda’s operations. Ten years after 9/11, al Qaeda in Yemen is stronger and perhaps better positioned to attack the United States.

Concern about civil liberties for the average American has risen sharply over the last decade since the 9/11 attacks. But Americans want government to err on the side of protecting them against possible terrorist attacks.

Carrying out the missions associated with securing four fundamental interests has been the raison d'être of U.S. military forces under presidents of both parties in times of conflict, of Cold-War competition, and in moments of relative stability and peace. Taken together, they define America's role in the world.

Ten years after 9/11, Americans fear there will be another attack. They also believe America is safer due to the government's efforts and that the initial decision to send troops to Iraq was the right one.

Vice President Cheney will sit down at AEI for a conversation about 9/11, the decisions made since, lessons learned, and lessons that have not been learned.

If the Obama administration succeeds in its plans to cut defense further, that percentage will drop to 3 percent or lower--the lowest total in the whole of the post-World War II era. But first, members of Congress and the American taxpayer want answers from Leon Panetta.