The National Security Archive‘s publication of the original powerpoint slides used in planning for war with Iraq has got a lot of attention, especially the prediction that by now there would only be 5,000 US soldiers in Iraq. But it’s also interesting as an index of tension with Iran.
The briefing includes several scenarios on what to do if a “triggering event” occurred before the completion of the ground forces deployment. These specify a range of options, from minimal, through a week-long Desert Fox-like campaign of air raids, up to a 14-day bombardment. This last one, option Red would have encompassed all suspected WMD targets and a range of military ones, and would have included 3,000 individual weapon aiming points from 2,100 aircraft sorties and a considerable number of Tomahawk cruise missiles. (See document E(pdf doc).)
So what does this tell us?
Well, an operation against Iran would require hitting a lot of nuclear-related sites around the country, and probably hitting them several times. It would also have the big difference from Iraq that there would need to be extensive counter-air activity to defeat the Iranian air force and suppress the ground defences. There would also have to be strikes on targets around the Straits, such as surface-to-surface missiles and radars. So it would probably be nearer “Option Red” in size than anything else.
Now, how do you get to 3,000? Each aircraft carrier group is meant to provide 100 sorties a day (in the NSA briefing slides – see below). It might be possible to concentrate three reasonably quickly, hence 300, as included in some of the other slides. From that force, you can also get 421 missiles. But you can’t use all of the possible sorties. If you assume that combat air patrols of at least four aircraft per group are needed for defence at all times, a strong assumption in this case, and that they are FA18s with a typical combat endurance of 1 hour, 45 minutes, you’ll need 13 reliefs – i.e. 52 sorties a day, or almost half the carrier air strength.
3,000-421 gives us 2,579 bangs to find. If the carriers could operate at maximum capacity for 17 days straight, it could be done, but this is unrealistic – after all, a proportion of the sorties will not find their targets, will have to turn back for technical reasons, will fail to make a tanker rendezvous, will be shot down, will miss and have to do it again, or will not take-off for whatever reason. A carrier air wing includes 50 strike aircraft, which implies a sortie rate of 2 for each aircraft, and more importantly, pilot. GlobalSecurity puts the “sustained” sortie rate at 125 per ship per day, so perhaps the briefing subtracted the air defence requirement? Doing that, though, would require an unsustainably high sortie rate per aircraft (and pilot) of 3, which will not be maintained for more than a couple of days. At a rate of 2, the carrier groups will provide 144 sorties a day other than defensive ones.
If we assume a 10 day campaign, and essentially two bursts of activity, we might assume a rate of 2 for seven days, or 1,008 strikes. Including the missiles, that leaves 1,571 planned strikes to find. At the same rates, that will require some 80 aircraft, either two more carrier groups, or a couple of land-based fighter wings. But that’s not at all.
If you check the US CENTAF communiquÃ©s, you’ll see that the existing air force in the region is flying about 80 sorties a day in support of ground forces in Iraq and Afghanistan (i.e. a rough requirement of 40-50 aircraft). I would suggest it’s reasonable to expect the demand for CAS to rise substantially if Iran is attacked, and that the value of this might be, say, 2.5 in Iraq and 0.5 in Afghanistan – so 150 or so a day, requiring 75 aircraft.
To put it another way – there will need to be a deployment of some 100 more combat aircraft, plus tankers and other support assets.