In 1956, French Prime Minister Guy Mollet suggested to British Prime Minister Anthony Eden that the two countries join together. When Eden hesitated, Mollet suggested that France at least be allowed to join the British Commonwealth. The French were willing to have joint citizenship with the British and even accept the Queen as their head of state.
Amazing. Even more amazing, Eden said "yes" to this last point, but then later went back on the suggestion. I’m still trying to wrap my mind around this.