Europe has a date with destiny this week. When leaders of the 25 European Union countries meet Thursday and Friday, they're expected to set a date to start EU membership talks with Turkey - for which Ankara has waited 41 years.
Absent a last-minute roadblock, their decision will go down in history as the point at which a mostly Christian culture decided it could reach out to a mostly Muslim one.
It also speaks to the EU's willingness to keep expanding, widening the very definition of Europe. In May, the EU took on 10 new members, mostly former East Bloc countries. Now it's considering three more in southeastern Europe: Bulgaria, Croatia, and Romania. If Turkey joined, the EU would stretch from Ireland to the border of Iran.
Certainly, there's resistance among some EU countries. They worry about a cultural oil-and-water mismatch. And they fear an avalanche of even more applicants after Turkey, overwhelming the EU's already creaking bureaucracy. In the back of everyone's mind is the voice of Ukrainian presidential candidate Viktor Yushchenko, who last week urged the EU to respond to Ukraine's courageous stand for democracy by offering it "concrete steps" toward membership.
But Europe's democratic and economic club should not shudder at someday admitting Ukraine. Nor should it fudge earlier promises to Turkey by offering a "privileged partnership" instead of full membership.
Embracing both these countries, as well as some Balkan states angling for membership, is in keeping with political trends reshaping the continent. The cold war is over, and with it the artificial division that cleaved Europe in two. The war on terrorism has begun, requiring a bridge between Christian and Muslim cultures - an ideal role for Turkey.
While forces external to Europe are at work, so are internal ones. The EU has come a long way since its 1952 origin as an economic community of six coal and steel nations. When EU leaders agreed on a proposed constitution in June, including a single foreign minister, they were endorsing the EU's evolution as a political entity - not merely an economic one. Increasingly, the Union is positively influencing fledgling democracies on its perimeter.
This week's momentous step with Turkey is achievable partly because it starts a long accession process - of perhaps 10 to 15 years. The time frame is actually a blessing. Turkey still needs to improve its human rights record and income levels. Europe needs to absorb its latest members, work out the mechanics of political union, and awake to the Muslim presence within and without its borders.
This evolution takes years, but there should be no stopping it.