This is what is wrong with this game. Every single player thinks he is some kind of an expert and mocks the new ones.

Those missiles were probably defused by someone who attacked you ( spy op - defuse missile). The other nuke was made ( while you play your turns there is a small chance you will produce a missile / you can improve that chance by getting warfare tech ).

Best to do for you is to join an well established alliance, just follow the alliance advertising ( or spam )that will follow my post.