Question

which event led to an heightened focus on national security?
○ the patriot act
○ war in afghanistan
○ september 11 attacks
○ the japanese treaty of 1960

Explanation:

The September 11 attacks (9/11) were a series of terrorist attacks on the US, which led to a significant and widespread heightened focus on national security, including the creation of new security measures and policies. The Patriot Act was a response to 9/11, the war in Afghanistan was also a response, and the Japanese Treaty of 1960 is unrelated to a broad heightened focus on national security in the context of modern counter - terrorism etc.

Answer:

September 11 attacks