Vice Adm. Michael McAllister, the U.S. Coast Guard’s top commander in the Pacific, recently said China’s new maritime reporting requirement was “very concerning” and violated “international agreements and norms.” In fact, McAllister added, if China chose to enforce the requirement, it would “begin to build foundations for instability and potential conflicts.” He expressed his concerns during a press briefing on Sept. 3. Foreign vessels entering what Beijing considers its “territorial waters” would be required to report their detailed information—including ship name, call sign, last and next port call, and current position—to China’s Maritime Safety Administration, according to the agency’s notice issued on Aug. 27. The reporting requirement went into effect on Sept. 1. The requirement would apply to four different types of foreign vessels—submersibles, nuclear vessels, ships carrying radioactive materials, and ships carrying bulk oil, chemicals, liquefied gas, and other toxic and harmful substances. Other foreign ships that “may endanger …