Here:
Senior Col. Zhao Xiaozhou, of the People’s Liberation Army’s Academy of Military Sciences, suggested in a question to Mr. Mattis that the U.S. Navy’s maneuvers near the islands could also be called militarization.
Like the US, China is free to conduct freedom of navigation patrols same as the US. That isn't good enough for China. It lays claim, illegally, to the whole area, and seeks to prohibit freedom of navigation in the area to everyone else. Building islands out of reefs and occupying them illegally and then militarizing them is proof enough of that.
Military confrontation is inevitable.
