18 USC 2331

(5) the term "domestic terrorism" means activities that-
(A) involve acts dangerous to human life that are a violation of the criminal laws of the United States or of any State;
(B) appear to be intended-
(i) to intimidate or coerce a civilian population;
(ii) to influence the policy of a government by intimidation or coercion; or
(iii) to affect the conduct of a government by mass destruction, assassination, or kidnapping; and
(C) occur primarily within the territorial jurisdiction of the United States; and

https://uscode.house.gov/view.xhtml?req=granuleid%3AUSC-prelim-title18-section2331&num=0&edition=prelim