One consequence of the Supreme Court's recent decision on presidential immunity may seem laughably quaint—its consequences for the Nuremberg Principles—collectively, the idea that the law could address, and thus deter, crimes against peace, war crimes, and crimes against humanity. These principles once mattered. At the end of World War II, it was the United States that insisted that, rather than simply execute leading Nazis, Germany's leaders should be publicly tried. The defendants, led by the Nazi's second most powerful man, Hermann Göring, mocked the court that ultimately convened in Nuremberg as merely a forum for victor's justice. But we disagreed....