On September 4, Judge Naomi Buchwald of the Southern District of New York dismissed an Alien Tort Statute suit against President Mahinda Rajapaksa of Sri Lanka, on the basis of a Suggestion of Immunity filed by the Justice Department, at the request of the State Department Legal Adviser. Under customary international law and longstanding U.S. practice, sitting heads of state or government are considered to have immunity from civil suits in U.S. courts.
Judge Buchwald’s decision is also notable for her rejection of the plaintiff’s argument that head of state immunity should not shield officials accused of jus cogens violations.
Source: J. B. Bellinger, Lawfare blog (click to see the whole post and for a link to the decision)