In the shadow of the global financial crisis, the European Parliament has plunged into a wholesale overhaul of Europe’s legislation to supervise its financial markets. From banks to insurance companies to credit-rating agencies, all are in the crosshairs of a nearly unanimous call for reform.

In early October, a preliminary vote for the overhaul sailed through the European Parliament, 565-74. Parliament has ordered bureaucrats in the European Commission to return with a legislative proposal by Nov. 30 and punctuated its urgency by copying the text of its report to national governments throughout the European Union and to the European Council of ...