My college major, decades ago, was economics. My current passion is politics. Little did I know those many years ago how intertwined economics and politics are. Take the European Economic Community, which, during my college years, was an experiment in economic cooperation. Later, the EEC became the European Union, increasingly connected politically as well as economically. Until last week, when French and Dutch voters flexed their political muscle and said, "Enough!" The economics of cooperation may be working, but the politics of national interests are powerful. As Europe showed us in the last century, the politics of nationalism can wreak havoc and the economics of cooperation can bring prosperity.

The "no" votes on the proposed European Constitution will seem minor compared to the politics surrounding the potential inclusion in the EU of Turkey, a NATO member lying in both Europe and Asia. Many Europeans worry about bringing a huge Muslim country into their midst, even though Europe has significant numbers of Muslim citizens. But, it's not just Europeans who have strong feelings about Turkey's joining the EU.

On a recent trip to Turkey, I interviewed Turks from both Europe and Asia and from all walks of life about their views on joining the European Union. Given the Turkish government's intense lobbying for membership, I was surprised by their responses. Here, too, the politics of nationalism is intertwined with economic interests.

There is an undercurrent of humiliation at Europe's treatment of Turkey's bid for EU membership, as if the Turks aren't good enough. Several people said Turkey should join the EU, but only when they're wanted. Others believe Europe doesn't see Turkey's value, so Turkey shouldn't join Europe. One man said that each time Turkey met European demands, Europe just added more. Europe was condescending, he pointed out, and didn't really offer Turkey much of value. Everyone spoke with nationalistic pride of Turkey's history, culture and values.

Other Turks see very pragmatic reasons for joining the EU. One shop owner told me Europe would force Turkey to follow the rule of law, and that was good. He said he used to pay taxes, but when he saw politicians pocketing his tax money instead of helping the country, he stopped. Corruption was a common theme. Another person told me how petty the corruption could be. He had sent flowers to a late friend's funeral and soon after received a call from an important local government official demanding he send more flowers in that official's name.

A man whose mother is Kurdish believes joining the EU will improve human rights in Turkey. Minorities are not treated equally by either the law or the government, he told me. Few people I talked to believed EU membership would offer personal economic rewards, partly because millions of Turks already live as migrant laborers in the richer European countries. They do believe, however, that EU investment would benefit their country over time.

As Europe and Turkey mull over future union for economic reasons, they would do well to heed the political realities of national interests and pride, of voters who may see their needs differently from the government. Like the United States, Europe is aging, and needs the influx of Turkish workers to fill low paying jobs. That is an economic reality. Turkish membership in the EU would make that easier. In return, Turks want investment and respect-and easier access to the jobs Europe offers them. These are both economic and political realities.

At a time when economic and political fractures between the West and Asia are growing more dangerous, the membership discussions between the EU and Turkey will be an important measure of how the politics of nationalism and the economic advantages of cooperation are managed in a key part of the world. This could well show us how bridging differences can enhance the common good or how stressing divisions can make those fractures worse. The outcome of this intertwining of politics and economics will deliver an important message to a watching world.