Rage is not a positive emotion. Rage is behind the phenomenon generally known as terrorism. And rage is the chief impulse in Islamism.

The terrible bombings in London will surely have brought back many emotions for people who lived in London during the troubles. I’m sure that many people – in a selfish way, perhaps – were immediately relieved that the perpetrators were not Irish.

The good news is that the Islamist campaign will abate when the rage abates, just like the IRA campaign receded when the outraged 1970’s generation of northern nationalists grew out of their anger.

The question that arises is: is the rage valid?

In Ireland the generation that spawned the Provos were subjected to horrific repression. They had been treated as second-class citizens for sixty years and when the inevitable violence arrived, the civilian population received the brunt of state repression. It sustained the IRA for years.

Eventually, the day-to-day grievances were addressed. Fair employment law, the Housing Executive, a moderation of state security forces; this all led to the ebb in nationalist rage.

Islamism too was born, and is sustained, by rage. Western imperialism took over every Muslim country on the planet. I can’t think of one Muslim country that wasn’t occupied by western countries at one stage or another.

The first response was nationalism. Then a mixture of nationalism and socialism. During the cold war Muslim countries across the globe became the plaything of the East and West blocs. Dictators of every depth of depravity were supported on both sides. The secular institutions that they created were discredited by corruption and fear.

At the same time the world was opened up to western culture by the global media. Societal norms and customs, lasting for centuries were held up to ridicule by modernist forces.

Also at this time, the population of Muslim countries exploded. An entire generation of young Muslims from Morocco to Indonesia were trapped in economies which could not offer them jobs or prosperity.

Into this heady mix stepped the ideology of Islamism offering old certainties and the lure of action and revenge. It must be pointed out that most Islamists, while supporting Sharia law and Islamic institutions, don’t support the wholesale slaughter of civilians. But every movement has its nutters and the Islamist movement has more than its fair share.

But while people in the west fear the Islamists, the truth is that they are going nowhere. You can’t run a society based on books written two thousand years ago. The west learned that a long time ago but not before Europe ran red with the blood of competing religions.

The Islamists are a negative force – they know what they are against but they have no chance of creating what they think they are for. You can’t corral society into a narrow ideology and keep it there. The separation of church and state has never looked so rational.

But while Islamism lacks credibility the rage that sustains it is all too real. Palestine is an open wound, for example, and the treatment of the Palestinian people is a scandal. Likewise, western support for repression across the Muslim world.

In the meantime, we are faced with wanton killing in the west. The worse possible response is to turn our countries into fortresses or to turn our backs again to the suffering of Muslims.

Unfortunately, that was precisely the response of the US to the 9/11 attack. Murder, kidnapping, rendering suspects to countries which use torture, detention without trial or accountability, and an invasion of Iraq where the US and the British don’t even count the Muslims they kill.

Even as the innocent dead of London are being buried and we wonder what will we do about it, the question is: will we add to, or subtract from, the rage?