New Delhi, Oct. 3 -- New York - Slovenia's president used the United Nations stage to say what many larger capitals still dodge. "We must stop the genocide in Gaza. There are no excuses anymore. None." The line, delivered from the General Assembly rostrum this week, was not a flourish. It was a demand from President Natasa Pirc Musar that governments treat international law as instruction, not ornament, and it traveled quickly on official feeds and broadcast clips from the UN's own channels.

The sentence has already become the week's shorthand because it does two things at once. It acknowledges Europe's historic failures to halt atrocity and it converts that memory into a present-tense duty. The president's words were captured in full by...