I've tried this many many times... I'm at war with Venice, and I've occupied all their mainland holdings. I want to go for an annexation, so I build a fleet, fight them and win, and when I'm about to land a siege force on the island, I just get a red X. The army doesn't budge from their ships, they just stand there stupidly. Why? I'm pulling my hair out in frustration. I've gone to the trouble of occupying every province they have on the mainland, and I can't attack one of the island cities. Can anyone help me?