Philippines President Rodrigo Duterte is called a “strongman,” and he likes the title. But he’s anything but strong.

Duterte’s fake tough-man persona was again proved on Monday as China invaded waters in the Philippines’ exclusive economic zone. While the invasion has taken the form of militia vessels rather than naval warships, it represents a deliberate and stark challenge to Filipino sovereignty. Evincing as much, defense minister Delfin Lorenzana offered his “grave concern” as to the Chinese action, adding that the fishing vessels are “violating our maritime rights and encroaching into our sovereign territory.” Manila has now made a diplomatic complaint to Beijing.