Lutèce is dancing.
This is a sarcastic comment that has lately become popular in diplomatic circles, referring to the recent string of balls at the Palais des Tuileries and the Palace of Versailles in Lutèce. Instead of arguing and brawling across the negotiation table as they usually do, the diplomats and military officers were spending all day at the dance floor. The naval disarmament conference had turned into an endless round of balls, which had earned this derogatory phrase.