I don't think Iran has the guts to do anything. Israel is just looking for a reason to nuke them out of existence. And no one in the world would care and they know it. Iran likes to talk tough but needs money like everyone else and not to get bombed out of existence and their defences trashed. They can slowly built a nuke themselves if they play nice. Just need time to do succeed without a hassle from the rest of the world and that isn't easy to accomplish with everyone watching them. Then they'll have a nuke like Israel and others and be equals.
And no I don't drink decaf but don't usually drink coffee at night unless I'm out somewhere. Doesn't seem to bother me when I do though. Usually just drink a lot of tea at night. Never drink water either so have to drink something.