Iran has beefed up greatly its anti ship missiles based on shore near the straights. Some are also on mobile launchers. Also they have massive amount of suicide small boats that can do great damage to our aluminum Navy escort ships for the carrier. CIWS is great, but it can run out of ammo if stressed by many targets at once. They (Iran) on has to get one little boat thru and a billion dollar ship can be disabled or sunk.

Right now our Navy is running on fumes and the pure numbers are lower than when Reagan took over. Obama was successful in reducing our naval size by over 30%!