To launch nukes before the SS launch, the sequence would have to be: Our nuke launch End of turn Other civs play. If ANY of them have a nuke, they hit us because the AI's always respond to a nuclear first strike with all the nukes they have that can reach the aggressor. I once had a mouse twitch and launched a tactical nuke straight up and back down on its launch point (got into "bombard" mode and didn't yet know how to get out of it) and all the AI's proceeded to hit me with ICBM's. If one or more of their nukes hit the city producing the SS part, it could be destroyed. Also existing SS parts can be destroyed by nukes Our turn comes up. If we are lucky and no SS parts are destroyed, and the city producing the last part still has enough shields, then we get to launch the SS, otherwise we don't launch, and have to rebuild any damaged parts. Besides, we can't watch any of it anyway, so what would be the point?