Deployed Nuclear Weapons and Force Structure-II

Recently, Sir Menzies Campbell wrote in the Financial Times that British nuclear doctrine should be redrawn in ways that might no longer require the Trident submarines that are currently the basis of Britain’s nuclear deterrent.  It was maintained that doing so would require abolishing the so called “Moscow criterion” that presumably drove force level requirements.

This “Nuclear Question” was the subject of the lead editorial of the Financial Times on May 19th.  In response, I submitted the following letter that was published in the 22 May 2012 edition:

Weakening Britain’s nuclear deterrent could come at a cost

Your 19 May editorial Nuclear Question lays the appropriate ground rules for the debate on the future of Britain’s deterrent: ‘First, Britain must not scrap its nuclear arsenal’, and most importantly, it ‘should only do so in multilateral negotiation with other powers. Second, it must stick to a sea-launched deterrent’  But the issue of the ‘Moscow criterion’ is a bit of a red herring.

During the cold war, Soviet ‘sophisticated air defenses’ had no capability against warheads delivered by ballistic missile and were not a factor in U.S. targeting. I doubt that this has changed.  The defense-offense balance would, however, dramatically shift if Britain eliminated its ballistic missile deterrent and relied instead on cruise missiles carried on conventional attack submarines to replace the Trident system.  A deterrent based on cruise missiles could well require higher force levels to compensate for their vulnerability.  Using cruise missiles, because of their range limitations, could also require the attack submarines carrying them to operate in areas where they would be more vulnerable. And last, but not least–and this alone should rule out their use–there is the confusion that would be introduced by any cruise missile launch: is the missile carrying a nuclear or conventional warhead? Bad idea.

While four Trident submarines would still be required for operational reasons (yes, one should always be at sea), the real issue is how many missiles must each submarine carry and how many warheads need be on each missile.  In the end, maintaining the Trident missile system may well be Britain’s most cost effective deterrent for the future.”