Abuse was sanctioned by a particular institutional attitude that has never been adequately challenged

In a celebrated speech at Westminster in 1959, then-Tory backbencher Enoch Powell suggested it would be a betrayal of everything England believed its colonial mission was about if the authorities tried to evade responsibility for the massacre of Mau Mau suspects at the Hola detention camp. More than 50 years later, a British government is still trying to evade responsibility for the torture of Kenyans in similar camps throughout the 1950s.

The government does not dispute that torture took place: it could not. The case has brought to light literally thousands of documents detailing how the authorities ignored and often collaborated in inhuman treatment of detainees. The argument is whether the British government now can be held responsible for the actions of a semi-autonomous colonial administration two generations ago. On Friday, the three surviving claimants of the four Kenyan detainees who began an action for compensation in 2009 were finally told their case could go ahead.

On the face of it this is a simple matter of justice. Whatever the context - and the Mau Mau were themselves responsible for the brutal murder of many Christian Kenyans - thousands, possibly hundreds of thousands, of people were interned and tortured into confessing their membership of the organisation. Senior colonial officials were entangled in their own double standards, privately acknowledging that any inquiry that exposed the brutality of the camps could fatally undermine any lingering legitimacy of British rule. Instead, they secretly colluded in abuse. It grew on, unchecked - until the Hola massacre occurred. After that, it was impossible to pretend it wasn't happening.

And that is the bigger reason why the government must stop procrastinating and accept responsibility for events that happened before many of its members were born. It is true that most of the officials involved are long dead. But it was not only a question of individual failure. Abuse was sanctioned by a particular institutional attitude that has never been adequately challenged. So, in differing ways, it has gone on: from the Malay emergency to Cyprus and from Northern Ireland to the war on terror.

It is a cliche to point out that challenges to state authority pose particular problems but still governments forget that the success that seems to its perpetrators to justify abuse turns out to be short-lived. Trying to uphold the rule of law by ignoring it doesn't work. Nor is admitting that we haven't always got it right the same as saying that everything British governments have done is wrong. As Enoch Powell recognised, the only possible way of sustaining trust is to admit when that trust has been betrayed.