A Ukrainian strike last weekend on an Iranian cargo ship in the Caspian Sea has underscored the links between the wars that the two countries are fighting, raising tensions between them as well as the risk of more direct confrontation. Ukraine said the ship was carrying military equipment between Iran and Russia. Iranian officials said it was a commercial vessel, and it accused Ukraine of killing a sailor in the attack. ................ Iran and Russia have had a close military relationship for decades. The most visible recent example of this is the long-range attack drones that Tehran has supplied to...