Many people welcome the recent growth in the power of international criminal tribunals. However, their track record should give cause for extreme concern about the way that this new supranational power will be wielded.

In democratic nation-states, the criminal justice system is embedded within the other structures of statehood, especially the legislature. Rules of procedure in British courts are rightly a matter for solemn debate in Parliament. Not so the existing international tribunals for Yugoslavia and Rwanda, which are subject to control by no parliament or electorate.

Anonymous witnesses, which the House of Lords has just ruled illegal for murder cases in Britain, are the norm at the Yugoslav tribunal, where no fewer than 40 per cent of prosecution witnesses give their evidence with their identity hidden. Such anonymous denunciation reminds one of the worst excesses of totalitarianism; it fatally undermines the right of defendants to cross-examine their accusers.

A culture of secrecy pervades these tribunals so that it is quite common for hearings to be conducted wholly or partly in secret, the transcripts hidden from the public for an indefinite period of time. Hearsay evidence is admitted, so that a defendant can be convicted on the basis of second or third-hand allegations which cannot be tested in court.

The trials are inexcusably long. The alleged ringleader of the Rwanda genocide, Theoneste Bagosora, was arrested in 1996 and the prosecution did not conclude its case until 2007, more than 11 years later. The trial continues even to this day. Such periods of detention, which are common, are simply incompatible with the presumption of innocence.

International tribunals use a theory of liability which is vague and dangerous. Defendants can be and have been convicted for war crimes they did not commit, did not order, did not know about at the time, and did not even intend. So-called "joint criminal enterprise" is a sort of conspiracy theory gone mad.

Power wielded without responsibility is incompatible with democracy and the basic principles of justice, especially equity. The Yugoslav tribunal never indicted its paymaster, Nato; the Rwanda tribunal prosecutes only Hutus and no members of the present government; and the overwhelmingly white lawyers at the new International Criminal Court have so far indicted only black Africans.

International tribunals are but the judicial wing of the new neo-colonialist Western policy of military interventionism in the internal affairs of other states: their power is dangerous and should be curtailed.

Taken from a debate at the ICA last week. John Laughland's A History of Political Trials from Charles I to Saddam Hussein is published by Peter Lang, Oxford