Mobile missile batteries are a challenge. They don’t have thousands of anti-ship missile batteries, though. They do have a lot. They aren’t the most sophisticated ASCMs in the world in terms of how easy it is to defeat each one (either hard or soft kill) but sheer numbers pose a problem.
We did a lot better at hunting SCUD launchers in Gulf War II than Gulf War I (where we essentially failed completely, but we did slow down the Iraqi launch rate because they had to spend so much time hiding.)
The massive experience hunting Taliban and whatnot over the last decade, as well as increased UAV use, will help a lot against mobile missile batteries.
One issue is you want the maximum number of ASCMs on a single target at the same time - that’s surprisingly hard to do, and will be even harder with limited or degraded C2 systems, as the Iranians will have. If two ships each face two volleys of 4 missiles 5 minutes apart, that’s much easier to deal with than one ship facing four volleys of 4 missiles all arriving within 30 seconds.
Really the most serious threat is probably mines, which have by far sunk or damaged the most USN ships since World War II, and which have been the most cost-effective weapon in naval history.
Hard to judge whether suicide boat swarms/small ASCM-armed missile boats vs. the shore-based missile batteries are the second greatest threat.
Good points about USN ships defending themselves. Not sure if that translates into defending tankers, though, since the tankers won’t even leave port after a state of war exists.
So it’s not enough that our USN ships can transit the straits: they must eliminate even the threat of Iranian ASCMs. That’s a much harder proposition. In my scenario, all the Iranians have to do is manage to launch a few ASCMs every few days, to keep the tankers from sailing. Hitting targets would only be a bonus.
In any case, 2012 is shaping up to be an “interesting” year.