There were two significant victories in the war on terror last week. Not only did the police round up the alleged suicide gang apparently responsible for the abortive attacks on London’s transport system on July 21, but the IRA also announced that it was ending its 35-year campaign against British rule in Northern Ireland. Both these developments come bristling with health warnings, but they are successes for policing and for a political and military strategy that finally defeated the Irish bombers.

Anything involving the provisional IRA needs to be approached with extreme caution. It will take a long time, perhaps years, to know whether the provos have actually done what they said they will do: how do we prove they have destroyed their stockpile of weapons and abandoned organised crime and punishment beatings? All this was meant to happen five years ago after the 1998 Good Friday accord. Instead the IRA obfuscated and delayed. One conclusion cannot be avoided, however — despite killing nearly 2,000 innocent people, it has not achieved its aim of a united Ireland. Terror has failed in Ireland, as it will fail when perpetrated by the Islamic fanatics on the mainland of Britain.

One reason for the IRA statement is that since the events of September 11 the world has changed profoundly. Terrorism is being seen for what it really is right across the West. The moral and financial support that the IRA drew from credulous Americans has dried up. Its involvement in the biggest bank robbery in Britain proved yet again that it was little more than a criminal organisation. Its responsibility and behaviour in the aftermath of the appalling murder of Robert McCartney revealed its true colours to anyone who still had any doubts. The IRA campaign of violence is another victim of Osama Bin Laden’s global jihad. The atrocities perpetrated by the Islamists, who seem increasingly to resemble the bizarre cults that have emerged in the West in recent decades, put politically motivated terror beyond the pale. There is a big gorilla on the block now and the monkeys are suing for peace.

The real challenge turns to defeating the suicide bombers. There can be little doubt that there are still killers out there other than the eight or nine so far accused. One has only to read accounts of the anger among Muslim youth to see that many are ripe for recruitment.

In the inquest that will go on after the atrocities of July 7, we should not forget that successive governments have played a role in fostering this alienation. Not only were the alleged July 21 bombers given sanctuary by Britain, but they went on to become part of our entrenched underclass. They failed in education, one was imprisoned and almost all lived off benefits. As social mobility has eroded in Britain, they turned to a corrupted Islam as their escape route. As this newspaper has said over many years, a prime purpose of government is to convert the underclass into a productive part of society. This is not easy, but it will not be achieved through misguided policies of multiculturalism and a benefit system that encourages indolence. For young Muslims it creates contempt for the lax moral values of the West and a desire for a purer existence. Hence there is a disproportionate high unemployment among Muslim youths who in turn provide bomb fodder for radical imams and Al-Qaeda recruiting agents.

Instead of its muddled policies, the government must tackle this problem at source with both stick and carrot. It needs actively to espouse the good in western and British culture, to engender pride, to abandon misguided multiculturalism, to provide better education and proper training and jobs for young Muslims. They must come to believe that their interests lie in and with Britain and not with a deranged creed that will bring death and despair to them and their many victims. This is a huge challenge for any government, but the consequences of failure are too great to contemplate.