"Any citizen of the United States, wherever he may be, who, without authority
of the United States, directly or indirectly commences or carries on any
correspondence or intercourse with any foreign government or any officer or
agent thereof, with intent to influence the measures or conduct of any foreign
government or of any officer or agent thereof, in relation to any disputes or
controversies with the United States, or to defeat the measures of the United
States, shall be fined under this title or imprisoned not more than three
years, or both."

Kerry met in 1970, by his own admission, with delegations from the North
Vietnamese communist government and discussed how the Vietnam War should be
stopped.