China has passed a new and unsettling milestone in the East China Sea, sending government vessels to waters near the Japan-administered Senkaku Islands for more than 100 straight days in what Tokyo has labeled a “relentless” campaign to take control of the disputed islets.

But more disconcerting for Tokyo than the milestone itself is the timing.

It comes at a precarious time for Sino-Japanese and Sino-U.S. ties. Washington is undergoing a radical shift in its policy toward Beijing, with Secretary of State Mike Pompeo using a speech Thursday to evoke images of a new Cold War and stating that the U.S. “can never go back to the status quo” in its dealings with China.