THE beheading of Nick Berg was an evil act of barbarism. Video footage of his execution will be one of the most haunting and lasting images of the conflict in Iraq.

US authorities have every right to pursue his murderers and bring them to justice.

However, the response from Coalition troops to the killing needs to be measured and restrained.

The US administration has told the international community that opposition to the military presence was supported by a very small minority of Iraqis.

It would be wrong, therefore, to seek retribution amongst the wider Iraqi population for a repugnant act by a handful of terrorist renegades.

At all costs the United States must avoid a revenge attack. Adopting such a tactic risks sparking a tit-for-tat cycle of violence, such as that which has destroyed hopes of securing peace and security between Israel and the Palestinians.

Instead, the US and Britain must focus their energies on tackling the cause of the militant opposition to their presence in Iraq.

The death of Mr Berg must not shake the resolve to establish peace in Iraq and a government run by Iraqis.

Meeting violence with violence will not restore Iraqi confidence in the process.

Nor will the increasing evidence of torture and humiliation inflicted on Iraqi captives.

Irrespective of Mr Berg's murder, the most constructive reaction to the crisis is to ensure that maltreatment of prisoners comes to an immediate halt, and that those British and American soldiers found guilty of these crimes are punished swiftly and justly.