Has a person elected to the US Presidency ever held a government position in a nation besides the United States?
I think any government-related role would be an interesting answer. I think the focus here is the role acts as a representative of the country, or to officially influence sovereign matters.
I do not think the role must have been voted by the people of that nation.
The most obvious examples would be three members of the Founding Fathers who served in roles for the British government.
George Washington served as both a member of the Virginia House of Burgesses which dealt directly with the royal appointed Governor of Virginia, and as a member of the British army.
John Adams was briefly a member of the Massachusetts assembly after the Boston Massacre.
Thomas Jefferson was briefly a member of the Virginia House of Burgesses.
After Washington, and Jefferson, it appears only two men who would become president served in any sort of meaningful capacity for a "foreign" government.
William Taft served another nation as the Governor-General of the Philippines, although he did so at the behest of the United States since it was a US colony at the time. For example, he negotiated on the behalf of the Philippines with the Roman Catholic Church over the purchase of Philippine lands.
Herbert Hoover was in charge of a large relief effort, the Commission for Relief in Belgium, during WWI that was international in nature. Technically, the commission was not a part of a government, but it did negotiate with foreign governments, and conduct diplomacy with the warring powers. After WWI he was in charge of the Supreme Economic Council which was run by the five victorious great powers from WWI.
President John Tyler served for the Confederacy after being president. (http://en.wikipedia.org/wiki/John_Tyler). The 14th amendment specifically prohibits former Confederates from serving certain offices (Specifically:
(Section 3) prohibits the election or appointment to any federal or state office of any person who had held any of certain offices and then engaged in insurrection, rebellion or treason. However, a two-thirds vote by each House of the Congress can override this limitation. ) (see http://en.wikipedia.org/wiki/Fourteenth_Amendment_to_the_United_States_Constitution)
Eisenhower perhaps qualifies, who was Military Governor of the U.S. Occupation Zone in Germany from the end of WW2 up to November 1945. He was responsible for the Joint Chiefs of Staff's directive 1067, the blueprint for rebuilding Germany after the war. He was responsible for distribution of food, medicine, dealing with the concentration camps and providing civil order/justice.
