The United States and Russia are scheduled to sign a new Strategic Arms Reduction Treaty (START) this Thursday in Prague. The previous treaty expired on 5 December 2009, making the absence of any treaty potentially more dangerous than signing one designed to be little more than face-saving. The Russians see it as a return to superpower status; the Americans have left open their development of a missile defence shield, thereby handing the Russians a reason to rip up the whole deal. We're back to the good old days!

There is also liable to be some confusion as this should really be called START III; START II was signed back in 1993 but was not ratified by the Russians in protest over US military actions in Iraq and Kosovo. But the thing that makes little sense about this new treaty is the absence of protocols on defensive systems. The whole nuclear arms race had a parallel, and equally important, surveillance race. The greatest tragedy would have been a nuclear holocaust started by accident, so that surveillance systems were developed which meant that neither side could launch a first strike without immediate retaliation. It even went so far that each side had personnel stationed inside each other's nuclear facilities. Surveillance is thus a form of defence.

Rather like two knights brandishing the latest in sword technology, they are more than likely to slay each other. But if one of them turns up in a suit of armour, they may still have parity of weapons but one side can inflict a lot more damage than the other. This makes me think that the whole treaty is the start of an altogether different nuclear balance. There are some knights missing from this particular tournament: one sits in Beijing, another in Tehran.