We are witnessing an exercise in lawless power - the strong bullying the weak.

Jack Straw's decision to let General Pinochet be extradited to Spain is not a victory for international law and justice. Instead, it inflicts severe damage on international law. We are witnessing an exercise in lawless power - the strong bullying the weak.

The gurus of international law claim that the Pinochet rulings are a step towards a more civilised world. Sovereign immunity can no longer be invoked to protect heads of state from prosecution for "international crimes". They claim that the decision is an important step towards the construction of an international system of justice.

This is simply untenable. In the past few weeks, during the period of the general's detention in Britain, three decisions on the same question have gone the other way. In both Belgium and France, appeals were lodged against President Kabila of the Democratic Republic of Congo (formerly Zaire) for crimes against humanity. They were rejected on the grounds that he was a head of state. He visited both countries on official business and left again without let or hindrance. And appeals lodged by Cuban exiles against Fidel Castro were rejected by Spain.

For serving dictators, therefore, the principle of sovereign immunity seems to remain valid. The House of Lords decision can thus only be taken to apply to people who have left office. The Pinochet decision sends a message to all dictators that they should never follow his example and relinquish office peacefully. It is far safer to remain in power and continue to kill with impunity.

For serving dictators, the principle of sovereign immunity remains valid.

Yet the very same "human rights" organisations which have campaigned for the general's prosecution for "genocide" have fought with equal vigour against identical charges being use to bar former communists from public life in the Eastern bloc. Similarly, the same Western powers calling for or facilitating General Pinochet's extradition are themselves in contravention of their own undertakings to hunt down those accused of crimes against humanity in Bosnia, which they refuse to do for political reasons. It is no coincidence that the supposedly judicial, but in reality highly political, Pinochet decisions were taken by a committee within a Parliament and by a minister in a Government.

If Spain wanted to extradite the general, it should have applied directly to Chile. By upholding the decision to arrest him in a third country, all the bilateral extradition treaties now in existence have presumably been rendered null and void. Instead of respecting the established rules of intercourse between states, two powerful countries, Britain and Spain, have in effect declared that their national judicial and political choices are superior to those of a smaller, weaker one. It is to prevent such an arrogant pretence that Article VI of the 1948 Genocide Convention (the very agreement under which the general is being prosecuted) stipulates that "persons charged with genocide ... shall be tried by a competent tribunal of the State in the territory of which the act was committed" or by an international tribunal.

All the bilateral extradition treaties have now been rendered null and void.

World history has seen many attempts to create planetary justice and universal monarchy. They have all foundered on the simple fact that it is better for laws to be enforced within the context of existing political communities than abstractly. Any body that brushes aside the principle of the equality of states and stands in judgment over another state becomes like a state itself. This opens up the question "Who guards the guardians?" In the new world order, in which judges hear cases while being allied to one of the parties, and where the law is capriciously invoked for reasons of pure political bias, the answer seems to be - no one.