GEOFF BENNETT: For more now on the U.S.

enforcement of the Strait of Hormuz blockade, we turn to retired Admiral Gary Roughead.

He was chief of Naval operations from 2007 to 2011.

He's now a distinguished military fellow at the Hoover Institution at Stanford University.

Thank you for being with us.

And I want to start with this, your reaction when you learned the U.S.

Navy fired on and seized an Iranian-flagged cargo ship near the Strait of Hormuz as part of the American enforcement there?

ADM.

GARY ROUGHEAD (RET.

), Former Chief of U.S.

Naval Operations: I was not surprised.

The blockade had been put in place, and as ships were moving in and out, if there was not enforcement of the blockade, it would be viewed as a paper tiger.

So, stopping a ship and boarding it was not unusual to me, given the circumstances.

GEOFF BENNETT: Where does firing on a vessel rank in the U.S.

toolkit for enforcing a blockade like this?

ADM.

GARY ROUGHEAD (RET.

): I would say it's ranked pretty high.

Normally -- and you heard in some of the videos that were released by CENTCOM that there were verbal warnings to the ship to stop.

Whether or not there were some shots fired across the bow to signal intent to use hostile force, I don't know.

I have not seen anything on that.

But disabling fire is quite high up the ladder.

But the fact remains that the blockade was enforced, the Marines boarded it, and my understanding now is that they're searching the containers that are on that ship.

GEOFF BENNETT: How operationally challenging is it to enforce a blockade in a body of water like that, given the size and the different entry points into it?

ADM.

GARY ROUGHEAD (RET.

): Right now, I'd say it's not very hard.

I mean, the intelligence that we have, the ability to be able to track ships, knowing where they're coming from, where they're bound, and the limited number of ships, because what we're doing is we're stopping either ships that have called at an Iranian port or are bound to an Iranian port.

So that number is fairly slow.

The sea lanes that they're -- fairly low.

The sea lanes that they're traveling on are well established, and in my mind it would not be a problem to be able to begin tracking that ship using aircraft, then passing that information to the ships that are in the region for an intercept to take place.

The volume is not high, the intelligence is good, so not that challenging.

GEOFF BENNETT: If the U.S.

wanted to keep the Strait of Hormuz open by force, what would that require operationally?

ADM.

GARY ROUGHEAD (RET.

): To keep it open by force under the current circumstances would require many more ships than are in place now.

It would require continuous air coverage of the strait, because not only are you defending against drones and missiles, but you also have to defend against small craft.

To move a large volume of ships in and out means that you would also have to start protecting those ships at some distance from the strait proper.

Ships that would be entering into the Gulf, you would have to pick them up and provide escort, and those that are leaving ports in the -- from the Arab Gulf states, you would most likely have to be able to provide protection for them moving through.

So until there's a cease-fire, a well-established cease-fire, an accepted cease-fire by countries that are engaged in commerce in the Gulf, it would require quite a bit of assets.

GEOFF BENNETT: And the U.S.

does not currently have those assets in place right now?

ADM.

GARY ROUGHEAD (RET.

): No, they're not.

GEOFF BENNETT: All right, that is retired Admiral Gary Roughead.

Thanks again for your insights and perspectives this evening.

ADM.

GARY ROUGHEAD (RET.

): Thank you.

Have a good evening.