Northern Irish peace process finally pays off

Looks like it's all over bar the shouting (and there will be plenty of that).

Earlier this week, the Rev Iain Paisley, firebrand loyalist leader of the Democratic Unionist Party, and Gerry Adams, (rumoured) former terrorist and now leader of the nationalist Sinn Fein, sat down together for the first time to declare their intention to form a joint government.

Great political divides still exist between them, but they are now to do with education, health, and "mundane" political issues, rather than bombs and guns.

It's been a long road - 10 years since the Good Friday Agreement which paved the way to today, with sideswipes into loyalist intransigence; republican deviousness and evasion of their agreed responsibility to decommission their weapons; together with the continued rumbling of organised crime (punishment beatings, armed robberies, etc) which have always been the mainstay of paramilitary fundraising in Northern Ireland (by comparison, "charities" like NorAid in North America were small beer), and the occasional bombing or shooting.

And before that, thirty years of mayhem and bloodshed. Along the way, the British government tried a shoot-first-ask-questions-later attitude, they tried imprisonment without trial or charge, they tried (with some success) covert operations and infiltration, and they tried muscular anti-terrorist rhetoric in public while holding secret talks with "the enemy" in private.

What are the key factors behind the apparent peaceful settlement of a one of the world's bloodiest terrorist problems of the modern era (the bloodiest in the developed world, prior to 9-11)?

Will the peace last?

What actions can be copied, or mistakes can be avoided, in the calming of other theatres in the War against Terror (however you define it? Which theatres? (E.g Israel/Palestine, Iraq, Afghanistan, etc.)