Quote Originally Posted by gilmore View Post
You are partially correct. The US Constitution prohibits US citizens who are government officeholders from receiving foreign titles without the approval of Congress. Ordinary US citizens can, and do, receive all sorts of foreign honors (or honours, depending on who is handing them out.) I am not aware of Congress doing so lately, not since World War II, when legislation was passed that allowed, I believe, anyone serving in the US armed forces to receive foreign honors.

Americans and other non-UK subjects are not knighted by HM the Queen, but that is a British custom, not American. Instead, they are given honorary knighthoods, as were Rudi Giuliani, Bob Geldorf, and many others.

Quite a few Americans are given knighthoods by the Knights of Malta, a sovereign entity, and papal knighthoods and titles of nobility, the Vatican also being a sovereign state. Or they were. I don't know if the present pope or the last one ennobled anyone. Pope John Paul II broke with tradition and didn't ennoble his own family. At the time he was quoted as saying something like, "They are Polish peasants. They wouldn't know what to do with a title."
And titles can actually be dangerous. At one time it was commonplace for Canadians to be awarded and allowed to accept British titles but there was a precedent-setting series of incidents recently when Lord Conrad Black wanted his Peerage and the Canadian Prime Minister of the day refused to allow him to accept it (they were political enemies). So Black got mad and gave up his Canadian citizenship, becoming Lord Black as a Brit, but later was convicted in a US court and held for extra years in a US prison because Canada could no longer claim him to fall under treaty agreements and transfer him here, where the prisons are nicer and parole much more generous. It can't seem like the best deal Conrad ever made, especially to him.