Observing Northern Ireland today, it's hard to recognise what was, just a decade or so ago, the theatre for such horror, barbarity, hate and bigotry. For 14 months now, old enemies have worked together - and even smiled at each other - when they had never exchanged a courtesy before.
Last year's historic agreement has so far stuck, and I believe will stick through ups and downs, precisely because it was brokered between the two most politically polarised positions - Ian Paisley's Democratic Unionist Party and Gerry Adams' Sinn Féin. But what are the lessons for international policy in other areas still locked in similarly bitter conflict and crippled by terrorism?
First, a need to create space and time, free from violence, in which political capacity can develop; second, identifying key individuals and constructive forces; third, the importance of inclusive dialogue at every level, wherever there is a negotiable objective; fourth, the taking of risks to sustain political progress, including by talking with enemies; fifth, the need to align national and international forces; sixth, avoiding or resolving preconditions to dialogue; seventh, gripping and micro-managing conflict resolution at a high political level, not intermittently but continuously, whatever breakdowns, crises and hostilities get in the way.
In the Middle East, the conflict has not been gripped at a sufficiently high level, over a sufficiently sustained period. Initiatives have come and gone, and violence has returned to fill the vacuum. International forces have not been aligned. Preconditions have been, and now are, a crippling bulwark against dialogue. However, despite the intensity of bitterness and hatred between Hamas and Israel, neither can militarily defeat the other - they will each have to be a party to a negotiated solution that satisfies Palestinian aspirations for a viable state and Israel's need for security.
Addressing Palestinian grievances - from security to jobs to housing - as we did in Northern Ireland, can create more fertile ground for a political process to complement engagement.
However, al-Qaida terrorism is fundamentally different. It is not rooted in political objectives capable of negotiation, but rather in a reactionary, totalitarian ideology completely opposed to democracy, freedom and human rights. Negotiation with al-Qaida and its foreign jihadists is, therefore, politically and morally out of the question.
Yet, offering individuals attracted to al-Qaida a non-violent, political avenue to address their concerns could conceivably help produce change in years to come. Northern Ireland's chief constable, Hugh Orde, only last week told the Guardian that discussions with al-Qaida "wouldn't be unthinkable, the question will be one of timing".
When the IRA's bloody armed campaign was raging more than 30 years ago, nobody in the British government could stomach talking with republican leaders except in surrender terms, since they were regarded as beyond the pale. Yet, in the middle of all this bloodshed and mayhem, contact was initiated which much later came to fruition.
Similar issues arise in Afghanistan, although the situation there of warlords attached to the Taliban for tactical reasons on the one hand, and the presence of al-Qaida leaders on the other, make the whole process especially complex.
The west urgently needs to match its commitment to global security with a commitment to global justice and global conflict resolution. The Northern Ireland experience, horrendous as it was, points to a rebalancing of foreign policy that can overcome horror with hope.
Peter Hain, MP for Neath and former secretary of state for Northern Ireland. A longer lecture on this subject, delivered today in New York, will be available at http://as.nyu.edu/irelandhouse.html.