Earlier quoted context omitted.
I'm a dual citizen of the UK and US. Among my close friends, I know Canadian, Israeli, and Australian dual-citizens. I've never heard of having to "renounce all other allegiances". (Note: it's entirely possible that there is some obscure method of obtaining US citizenship that requires it; but that's not the norm.)
I'm a dual Canadian/U.S. citizen, although I was born so in both countries (born to American parents on Canadian soil). I've never once had to worry about this whole renunciation thing. Additionally, my brother became a Canadian citizen (born U.S.), and again had no problems; Canada didn't care about his U.S. citizenship, and the U.S. doesn't care about his Canadian citizenship. He could officially renounce his U.S.…
If America would get a draft again, could a dual citizen be drafted?