Russia's decision last week to abandon the START 2 treaty on nuclear missiles was to be expected after the United States announced it is to develop an anti-missile defence system. It follows the treaty signed in Moscow last month in which Presidents Bush and Putin agreed to cut the nuclear warheads deployed against each other to one third their present number by 2012.
These decisions effectively abandon the Cold War doctrines of containment, nuclear parity and deterrence. But they do not necessarily make the world a safer place.
President Putin has chosen a bold path of accommodation with the US following the attacks on New York and Washington last September. This has allowed the Russian leader to make the best of a weak hand, arguing that the former antagonists now have shared enemies of trans-border terrorism and criminality. In order to consolidate Russia's political and economic development he needs stable and trustworthy relations with the US and with other European states. That, he argues convincingly and effectively, is best achieved by political engagement.
Hence Mr Putin's willingness to transform relations with NATO in a much more political direction, taking them away from the confrontational system of the Cold War and towards a system of common security in Europe. He puts this argument to his more conservative military establishment, even if he agrees with them in criticising NATO enlargement to Russia's borders, which is likely to be decided at a summit in Prague this autumn. It is a balancing act made more difficult by the parallel enlargement of the European Union, which is set to impose strong border controls isolating the Russia's Baltic enclave, Kaliningrad, from neighbouring Poland and Lithuania, as well as on Ukraine and Belarus.
Changing nuclear doctrines in these ways raises important questions about whether they make the world safer from these terrible weapons. One of the long-standing objections to an anti-missile defence system is that it could make one side so invulnerable to attack as to contemplate their first use. News that President Bush is about to authorise a change in US policy to allow pre-emptive strikes on states suspected of developing chemical, biological or nuclear weapons would seem to confirm such fears. Along with the alarming recent tension between India and Pakistan, both of them nuclear powers, these changes deserve the closest international attention.