A single US law bans citizens from private diplomacy
In 1798, a Quaker doctor traveled to Paris to prevent a war with France, inadvertently sparking a legal ban on freelance diplomacy that remains active today.
Dr. George Logan arrived in Paris with nothing but a few letters of introduction and a desperate desire to prevent a full-scale war between the United States and France. At the time, French privateers had already seized hundreds of American merchant ships, and official diplomatic channels had completely collapsed. Logan's unauthorized peace mission actually worked, leading to the release of American sailors and a lifting of the trade embargo. However, when he returned home, the Federalists in Congress were outraged that a private citizen had usurped the government's role. They responded by passing the Logan Act in 1799, making it a crime for any citizen to influence the conduct of a foreign government without official permission.