HOME Secretary Theresa May is to be congratulated on making the correct decision in refusing to extradite Gary McKinnon to the US.

Claims that this is a victory for common sense and compassion on behalf of someone who has Asperger's syndrome and deemed at high risk of suicide, however, must be tempered by the fact that the 46-year-old computer geek has spent the last 10 years of his life in a permanent state of anxiety about his fate.

The case of Mr McKinnon (and those of several other UK citizens wanted for prosecution in the US for alleged crimes committed in Britain) confirms that the extradition treaty between the UK and the US is seriously out of kilter.

Mr McKinnon has admitted hacking into dozens of Pentagon and Nasa computers from his London bedroom. He was neither terrorist nor criminal but on an obsessive hunt for evidence of UFOs. However, US officials have insisted that he should be prosecuted for the expensive trail of damage caused during what they describe as the biggest military hack of all time.

The legislation Britain passed in the wake of the 2001 attacks on the Twin Towers to facilitiate the extradition of terrorists to the US was a lop-sided arrangement. It allows British citizens to be seized on the basis of a warrant, while the authorities here must demonstrate they have a good case to bring an American to Britain. International recognition of an obligation to extradite or prosecute someone accused of terriorism or a serious international crime is essential. But that should not override the principle that someone accused of committing a serious international crime in or from this country should be prosecuted here.

Mrs May has indicated that British courts will have the power to bar prosecution overseas if they believe it is in the interests of justice to do so. This forum bar is a step towards common sense and, by airing the arguments in open court, should enable justice to be seen to be done. The lengthy delays as extradition cases go through the appeals system are a serious affront to justice. It has taken 10 years to decide Mr McKinnon should not be extradited, despite having Asperger's syndrome and an increasingly fragile mental state. Abu Hamza, the radical Islamist cleric and four other suspects were extradited to the US last week to face terrorism charges after appeal processes that took up to 14 years. Unsurprisingly, this was branded unacceptable by High Court judges.

One of those extradited was Babar Ahmad, a British citizen accused of raising funds for terrorism from his London home. His case is entirely different from that of Abu Hamza and prosecution would have been likely to pass the "interests of justice" test. This highlights the need for individual assessment that is also evident in the case of Richard O'Dwyer, accused of copyright offences.

The steps announced yesterday will lead to improvement but the imbalance in the standard of proof required between the US and UK cannot continue. Although Mrs May wants to transfer the power to block extradition on human rights grounds to high court judges, there is a value in the sanction being retained by the Home Secretary, who is answerable to Parliament. #

There is agreement that the process is in need of transparency and fairness but the importance of accountability must not be overlooked.