What U.S. military operation was launched in 2001 in response to the September 11 attacks?

The operation launched in 2001 in response to the September 11 attacks is Operation Enduring Freedom. This military campaign was primarily aimed at dismantling the al-Qaeda terrorist network responsible for the attacks and removing the Taliban regime in Afghanistan that provided safe harbor to al-Qaeda.

Operation Enduring Freedom began on October 7, 2001, just weeks after the attacks, as a coordinated effort by U.S. and allied forces to engage in combat operations against terrorist targets and to stabilize Afghanistan. The overarching goal was to prevent future terrorist attacks and establish a democratic government in Afghanistan.

The other operations mentioned serve different purposes and contexts. Operation Desert Shield was part of the response to Iraq's invasion of Kuwait in 1990, leading to Operation Desert Storm. Operation Iraqi Freedom refers to the U.S.-led invasion of Iraq in 2003, which was largely based on the belief that Iraq possessed weapons of mass destruction. Operation Noble Eagle involves the defense of U.S. airspace and air defense alert missions following 9/11. Each of these operations is significant in its own right but does not pertain specifically to the immediate military response following the September 11 attacks.