U.S. President Barack Obama has named Dr. Jim Yong Kim as his nominee to lead the World Bank. In the past, that would have been the end of the process — Washington spoke and the bank complied. It is still probable that Mr. Kim will assume the post in June when it becomes vacant, but old certainties are eroding.

That is a good thing. The idea of such a prominent post being a U.S. sinecure is quaint and outdated. More importantly, it does not guarantee that the best person gets the job. And for a position as important as World Bank president, nothing is more important.

The World Bank was set up, along with the International Monetary Fund (IMF), in the frenzy of international institution building toward the end of World War II. Historically, an American has always headed the bank, while a European occupied the top post at the IMF. That practice has come under criticism in recent years as other countries challenge the award of the post on the basis of nationality and as those other governments take an increasingly significant stake in how those organizations are run.