Twenty-second Amendment to the United States Constitution
The amendment prohibits any individual who has been elected president twice from being elected again. Under the amendment, an individual who fills an unexpired presidential term lasting greater than two years is also prohibited from winning election as president more than once. Scholars debate whether the amendment prohibits affected individuals from succeeding to the presidency under any circumstances or whether it only applies to presidential elections.
French nationality law
In 2001, as Bill Clinton finished his second term as President of the U.S. (the legal limit of terms under the U.S. Constitution), a theory was published by CNN that he could claim citizenship of France and run for leadership there. The open-letter by historian Patrick Weil held that a little known "law, passed in 1961 [article 21-19(5º)], enables people from former French territories to apply for immediate naturalisation, bypassing the normal five-year residency requirement for would-be French citizens." As Clinton was born in Arkansas which had been part of French Louisiana before it was sold to the US, it was held that he would qualify under this law. And as a naturalised French citizen, he could run in the French presidential election.