The Justice Department announced late last week that a subsidiary of Duke Energy has agreed to pay $1 million for killing golden eagles and other federally protected birds at two of the company's wind projects in Wyoming. The guilty plea was a long-overdue victory for the rule of law and a sign that green energy might be going out of vogue.

As Justice noted in its news release, this is the first time a case has been brought against a wind company for violating the Migratory Bird Treaty Act. The 1918 law makes it a federal...