Great! This will allow me to win the game that I plan to finish this weekend. I haven't prepared anything yet, but the French capital is just across a narrow channel, so I should be able to take it within a few turns.
More generally, I suppose it is best to delay taking the enemy capital and pushing that "cancel button" in their space control centre as long as possible. The sooner their ship is destroyed the sooner they can start building a new one, can't they?
Anyway, thank you for sharing your experience. It really makes me look forward to finishing that game now.