[LexBaird]

You can't be a knight of the realm and use the title Sir unless you are a UK citizen,

Robert Mugabe, butcher of Zimbabwe, is a Knight Commander of Bath.

[agere_contra]

Robert Mugabe, butcher and marxist-kleptocrat of Zimbabwe, is a Knight Commander of "the Order of the Bath", not of Bath.

I can see the confusion: "Prince of Wales", "Duke of Edinburgh", etc, but not "Knight of Bath". The Order of the Bath is a specialist honour with an entertaining royal provenance - I'm sure Google will have the details.

[Vectorian]

Oh yes, anyone can get a KBO, a proper knighthood requires you to be British. Even your Colin Powell is a KBO! :)

[F.J. Mitchell]

LOL! Knighthood seems to have achieved the same level of respectability and honor as the present day Nobel prize.