One of two nations to do so, actually: you're forgetting Canada...
Perhaps so - I know that US nuclear weapons were stationed there during the Cold War for air-defence purposes, and I suppose it's possible that the Canadians had sole launch authority for them. But I wasn't aware that Canada had produced and deployed it's own nuclear arsenal, or that it had been voluntarily retired. If that is the case, it's certainly a very well-kept secret.