The French nuclear attack submarine Emeraude recently made a port call at Guam’s U.S. naval base. It’s a welcome show of French support for the U.S.-led efforts to resist Chinese imperialism in the South China Sea.

France is well aware that China will react poorly to this deployment, as with Emeraude’s recent submarine warfare exercise alongside the Australian navy. But in a break with French naval protocol, which generally avoids commenting on submarine deployments, Emeraude’s visit to Guam has been publicized. That proves this is a calculated signal to Beijing that the French government is increasingly concerned by China’s South China Sea strategy.