What psychological shift occurred after the terrorist attacks on 9/11?

America as a whole became “paranoid”, and declared a “war on terrorism”

More than 3,000 individuals from seven US cities reported on their memories of learning of the terrorist attacks of September 11, as well as details about the attack, one week, 11 months, and/ or 35 months after the assault.

The league of nations was found in 1919 to keep peace after world war l.but it failed to prevent world war ll in 1939,so in 1945 the nations of the world set up a new organization,the united state (un).since then, the un has encouraged international cooperation and worked to resolve conflict