What was one of the effects of September 11th?

One of the significant effects of September 11th was the implementation of heightened security measures, particularly in air travel and public spaces. The U.S. government established the Department of Homeland Security and enacted the USA PATRIOT Act, which expanded surveillance and law enforcement powers. Additionally, the attacks led to increased anti-terrorism initiatives globally and shifted U.S. foreign policy, resulting in military actions in Afghanistan and Iraq.