Comment Tomorrow, the new National Security Council meets to decide just what the future armed forces of the United Kingdom will have in terms of people and machines - how many regiments, tanks, guns, jets, choppers, ships and submarines, and of what type.

As at most meetings where major issues will be decided in a short space of time, the major decisions have already been made, at least in outline - and are leaking into the media.

Thus it is a good bet that the first of the two new carriers for the Royal Navy will go ahead. The second may be downgraded to serve as an amphibious-warfare ship full of troops and helicopters rather than combat aircraft, or it might be cancelled altogether - which means British shipbuilding would be kept alive by bringing forward plans for a new generation of navy frigates.

The RAF and even the Army will be offering up massive cuts of their own - it is expected that the entire Tornado deep-bomber fleet will be retired years early, and the current Cold War style armoured-warfare juggernaut of tanks, mobile artillery and infantry fighting vehicles is set for a major trim back - so there is only one way that the government can preserve a two-carrier navy.

That one way is to finally cut the Royal Navy's force of frigates and destroyers - collectively known as "escorts", as their primary role is to protect and defend major warships - down to numbers suitable for actually escorting our biggest ships. For the past many decades, for reasons of history and jobs for the boys, the RN has actually maintained far more escorts than it needs to escort major units such as carriers and amphibious task groups.

Realistically, a combat carrier can actually protect herself using aircraft far more effectively than her escorts can: but it is reasonable to say that sending a carrier out to a major war alone, when just one bomb or missile or torpedo could eliminate Britain's reach into a given theatre - perhaps cutting off air cover, supplies, even the chance of evacuation for our troops ashore - is a gutsy call.

So send out a carrier with some escorts, by all means. Send her out accompanied by a new Type 45 destroyer, whose Aster missiles (once they are finally declared operational) might offer some chance to shoot down incoming Russian-made shipkillers that have somehow evaded the carrier's airborne radar and thus not been shot down easily by patrolling fighters*.

Merlin sub-hunter helicopters aboard the Type 45 and the carrier should in fact provide all the protection one could possibly need against enemy submarines, assuming any actually exist. But let's make doubly sure, and send a couple of Type 23 frigates - the RN's most sophisticated sub-hunting ship - as well.

Having two carriers means that we'll always have one up and operational, so enemies won't simply wait until our one carrier is in refit before becoming annoying. Generating an escort force for one carrier can't possibly call for more than nine escorts - and we have been generous here, allowing three ships to produce one up rather than two for one up as is apparently quite achievable for the carriers themselves.

The carrier and her escorts will dominate hundreds of miles of sea surface and airspace, enough that we can send supply convoys and amphibious ships in and out of the warzone without fear of air or missile attack. These other vessels can also carry Merlin antisubmarine choppers should there be subs about, and the carrier could always detach a frigate too. Furthermore, air dominance effectively cripples any enemy submarine that lacks nuclear propulsion. So there's no great need to fret about subs.

Yes, there would be more risk to be faced tackling an enemy with strong submarine and air/missile forces, than there would be for an RN with a huge fleet of escorts. But such enemies don't actually exist; if they did they'd be likely to have nuclear weapons. So let's not panic too much about that.