The Foreign Sovereign Immunities Act - Title 28, 1330, 1332, 1391(f), 1441(d), and 1602 1611 of the United States Code places limits on suing foreign sovereign nations in State or Federal courts.
The law should not include exceptions for state-sponsored terrorism.
These offences are direct attacks against a nation and are covered within context of any other attack on the nation or its people.