And finally, at the ripe old age of 80, Paisley faces a stark personal choice: Does he want to be remembered only by history as an uncompromising obstacle to peace, or does he want to crown his career by becoming leader of Northern Ireland?
Despite all those arguments for compromise, Paisley and McGuinness still have a tough job in the next two months convincing enough of their followers that power-sharing with the enemy does not mean selling out. The writer Brendan Behan once joked that the first item on the Irish political agenda is always "the split" -- and Paisley and McGuinness will desperately want to avoid the sort of internal splits that were disasters in the past, such as the IRA split in 1969 and the frequent splits on the loyalist side.
So far, Sinn Fein and the IRA have been skillful in marginalizing the remaining IRA extremists and die-hards. While endorsement of the police is still contentious (many republicans still blame them for earlier killings of Roman Catholic residents, either directly or through Protestant paramilitary forces), the fact is that the Northern Ireland police force is one of the most reformed in the world, and a recent poll showed that even 80% of nationalists accept it.
For his part, Paisley is facing down fundamentalist dissidents in the Democratic Unionist Party who have vivid memories of atrocities ordered by McGuinness' IRA. Yet the odds are that Paisley will prevail within his own party for one simple reason: Unlike all previous loyalist compromisers, he doesn't have a Paisley on his flank to undermine him.
The next step is for Sinn Fein to convene a national convention later this month to accept the proposals on the police. This would be followed by elections to the new Northern Ireland Assembly on March 7. If all goes according to plan, the long-standing fomenter of anti-Catholic and anti-Irish bigotry will on March 26 share the leadership of Northern Ireland with a former IRA terrorist.
If they both use their extraordinary political skills to find common ground, the coalition should survive and stand as a tribute to the painstaking diplomacy of all those from Ireland (North and South), Britain and the United States who worked for decades to make peace possible.
The peacemakers in the Middle East should take heart.
