The global war on drugs "is causing more harm than drug abuse itself", the UN Secretary-General has been warned by international judges, senior politicians and other dignitaries.
In a letter being delivered today to Mr Kofi Annan, on the eve of the opening of a UN General Assembly session on drugs, the group calls for an end to anti-drugs policies which have cost billions of pounds but achieved little.
"Persisting in our current policies will only result in more drugs abuse, more empowerment of drug markets and criminals, and more disease and suffering," the letter reads.
Among the thousands of international signatories are the former UN secretary-general, Mr Javier Perez de Cuellar; the former prime minister of the Netherlands, Mr Andreas Van Agt; the European Commissioner for Humanitarian Affairs, Mrs Emma Bonino; the former presidents of Bolivia and Colombia; writers Ariel Dorfman and Dario Fo; and philosopher Ivan Illich.
The Irish signatories include Prof Ivana Bacik, criminal law professor at Trinity College Dublin; Mr Tim Murphy, law lecturer at UCC; legalise cannabis campaigner Mr Olaf Paul Tyransen; and journalist Mr Vincent Browne.
The signing of what will be the largest international call for a reappraisal of drugs policies has been co-ordinated by the Lindesmith Centre, a project of the Open Society Institute sponsored by the international financier, Mr George Soros.
The letter says the UN has a legitimate and important role to play in combating the harms associated with drugs, "but only if it is willing to ask and address tough questions about the success or failure of its efforts".
It asks bluntly what drug war policies have achieved to date.
"Every decade the United Nations adopts new international conventions, focused largely on criminalisation and punishment, that restrict the ability of individual nations to devise effective solutions to local drug problems. Every year governments enact more punitive and costly drug-control measures. Every day politicians endorse harsher new drug war strategies.
"UN agencies estimate the annual revenue generated by the illegal drug industry at $400 billion, or the equivalent of roughly 8 per cent of total international trade. This industry has empowered organised criminals, corrupted governments at all levels, eroded internal security, stimulated violence and distorted both economic markets and moral values. These are the consequences not of drug use per se, but of decades of failed and futile drug war policies."
It says that in many parts of the world "drug war policies impede public health efforts to stem the spread of HIV, hepatitis and other infectious diseases. Human rights are violated, environmental assaults perpetrated and prisons inundated with hundreds of thousands of drug-law violators.
"Scarce resources better expended on health, education and economic development are squandered on ever more expensive interdiction efforts. Realistic proposals to reduce drug-related crime, disease and death are abandoned in favour of rhetorical proposals to create drug-free societies".
In a separate statement, the Lindesmith Centre compared favourably the Dutch approach to drugs to the US's repressive policies. It said fewer people smoked marijuana or used heroin in the Netherlands despite spending less on drug enforcement.
The centre, established in 1994, has called for a move towards harm-reduction policies like syringe exchanges, although it has stopped short of urging the decriminalisation of drugs.
The letter concludes by calling on Mr Annan to initiate "a truly open and honest dialogue . . . one in which fear, prejudice and punitive prohibitions yield to common sense, science, public health and human rights".
