Canada had a policy up into the '70s of not allowing dual citizenship, so I am told. However, both Canada and the U.S. allow it. They don't officially *encourage* it, but they allow it.

The disadvantages are relatively minor for most people: If I as a dual citizen am detained in the United States, the government of Canada does not have as much influence in my case as if I were solely a Canadian citizen.

One big advantage is that no matter which way I go across the U.S.-Canadian border, I'm "coming home" and am less subject to bureaucracy at the border station.

I can travel on a Canadian passport to some locations barred to an American passport. In the end, having citizenship connections to more than one country makes my life richer, rather than reflecting inability to make a commitment.

Just my USD $0.02 or CDN $0.03 (or CDN $0.04, all up with HST).