How did the united states respond to the terrorist attack on september 11, 2001? president bush invaded iraq to prevent saddam hussein from occupying saudi arabia. president bush authorized operation enduring freedom and invaded afghanistan. president bush invaded all countries that had active terrorist cells. president bush placed an embargo on all goods exported to afghanistan.

President Bush authorized Operation Enduring Freedom and invaded Afghanistan in response to the terrorist attack on September 11, 2001.

Explanation:

"Operation Enduring Freedom" is the official name used by the United States Government for the Afghanistan War, along with a number of smaller military actions, in the context of the "War on Terror."

In response to the September 11 attacks, the first combat operations that took place on October 7, 2001 included a mixture of attacks using B-1 Lancer, B-2 Spirit and B-52 Stratofortress ground-based bombers, military aircraft, and Tomahawk cruise missiles launched from both US and British submarines and warships.

The initial military objectives of the OEF, as presented by President George W. Bush in his September 20 speech to a joint session of Congress and his speech on October 7 to the country, included the destruction of terrorist training camps and infrastructure located in Afghanistan, the capture of al Qaeda leaders and the cessation of terrorist activities in Afghanistan.