In the case of Opati v. Republic of Sudan, the U.S. Supreme Court ruled unanimously in 2020 that punitive damages can be awarded to victims of terrorist attacks sponsored by foreign states, even if those events occurred before Congress expressly authorized such awards in 2008. The decision came as a result of a lawsuit filed by families and survivors affected by the 1998 bombings at U.S embassies in Kenya and Tanzania which were orchestrated by Al-Qaeda but allegedly facilitated through material support from Sudan's government. Initially, lower courts had denied these plaintiffs' claims for punitive damages on grounds that they weren't explicitly permitted under federal law when the bombings happened; however, this ruling was overturned with Justice Neil Gorsuch writing for the court stating that Congress clearly intended its amendments to apply retroactively.

In the dissenting opinion for OPATI v. REPUBLIC OF SUDAN, Justice Brett Kavanaugh disagreed with the majority's interpretation of a 2008 amendment to the Foreign Sovereign Immunities Act (FSIA). He argued that Congress did not intend this amendment to apply retroactively and allow punitive damages for past acts of terrorism. Instead, he believed it was meant only to clarify that foreign states could be held liable for future terrorist attacks. Kavanaugh pointed out that there is a presumption against retroactivity in American law unless Congress explicitly provides otherwise, which they did not do in this case. Therefore, he concluded that Sudan should not have been ordered to pay billions of dollars in punitive damages for its role in the 1998 embassy bombings.