The defence review to be announced by the British government this week is likely to include a reprieve for the Royal Navy's two new aircraft carriers currently being built.

The Navy PR machine has been in overdrive recently explaining to anyone who will listen why they are essential to Britain’s military capability.

The reality is that there is little military rationale for continuing with this white elephant of a project. It is about protecting jobs and continuing to give Britain a shipbuilding capability, a worthy end in itself, but little to do with the UK effectively being able to 'punch its weight' . For the really shocking thing about this decision is not only are these ship unaffordable, they are already obsolete before they're even built.

The military case for producing bigger and bigger ships just doesn't stack up. Even America, the largest, most powerful Navy in the world, is asking serious questions about the aircraft carrier as a way of projecting power in the future. It's a pity they never bothered to tell their allies. US Secretary of Defence Robert Gates is on record expressing reluctance to invest in any more aircraft carriers due to the increasing sophistication of anti ship missiles now being produced. Anti ship missiles that when they come into service in the next couple of years, the US or anyone else will have no effective defence against.

The DF-21D being developed by the Chinese flies faster, has a longer range and a bigger warhead than any equivalent missile. This next generation missile will be designed as space entry and exit warhead giving it speeds of up to 2km a second, far faster than any missile defence system can cope with or is likely to be able to cope with even in the medium term. As John Patch Professor at the US Army War College said: 'Everyone in the Western world is wondering how you defeat it.' Everyone it would seem apart from the Royal Navy who are head in sand pressing ahead with a project that has everything to do with false vanity and nothing to do with military practicality. Anyone with access to this missile will be able to send HMS Queen Elizabeth and HMS Prince of Wales straight to the bottom of the sea and there's nothing anyone will be able to do about it.

It is now dawning on naval strategists that just like the once all conquering battleship before them, advances in technology have made aircraft carriers obsolete. In the future missiles like the DF-21D and its successors will have made them too easy to sink, just as advances in air power and the invention of these very aircraft carriers put the nail in the coffin of the battleship as a fighting unit. As usual though UK military planners are investing in fighting today's wars tomorrow, rather than planning for tomorrow's wars today.