can a us citizen hold a foreign title
The Title of Nobility Clause is a provision in Article I, Section 9, Clause 8 of the United States Constitution, that prohibits the federal government from granting titles of nobility, and restricts members of the government from receiving gifts, emoluments, offices or titles from foreign states without the consent of the United States Congress. Also known as the Emoluments Clause, it was designed to shield the republican character of the United States against so-called ``corrupting foreign influences''. This shield is reinforced by the corresponding prohibition on state titles of nobility in Article I, Section 10, and more generally by the Republican Guarantee Clause in Article IV, Section 4.
Title of Nobility Clause