Which legislation allowed for expanded surveillance of foreign communications?

The Foreign Intelligence Surveillance Act (FISA) is the correct answer because it specifically established the legal framework for the surveillance of foreign communications, particularly those that may involve threats to national security. Enacted in 1978, FISA allows for the investigation of foreign powers and agents of foreign powers, authorizing the collection of intelligence through electronic surveillance and physical searches.

Over the years, FISA has been amended to adapt to changing technologies and threats, including significant updates in the wake of the September 11 attacks, which further expanded the government's ability to monitor foreign communications. The Act balances the need for national security with the protection of civil liberties, requiring oversight by the Foreign Intelligence Surveillance Court to ensure that surveillance is conducted legally and that the privacy of U.S. citizens is protected when applicable.

In contrast, the USA PATRIOT Act focused more broadly on domestic security measures and did include provisions affecting surveillance but was not solely limited to foreign communications. The Security and Freedom Enhancement Act mainly addressed civil liberties in the context of national security but did not specifically legislate foreign surveillance. Lastly, the Intelligence Reform and Terrorism Prevention Act enhanced coordination and intelligence-sharing among various agencies but did not primarily establish the framework for surveillance of foreign communications as FISA does.