A Chinese spy ship observed the United States’ first-ever test launch on July 12 of a Terminal High Altitude Area Defense (THAAD) interceptor missile against an intermediate-range ballistic missile-class target. According to CNN, which first reported the Chinese ship’s presence, the ship had “been sailing in international waters off the coast of Alaska for several days,” having arrived in the area before the THAAD test. The U.S. Missile Defense Agency had suggested that a THAAD test would take place soon in the first week of July, but did not specify a time for the test.
The Chinese vessel was most likely a People’s Liberation Army-Navy (PLAN) Type 815 auxiliary general intelligence ship. Specifically, the vessel is most probably the PLAN Tianlangxing, with pennant number 854, which was reported days before the THAAD test to have transited the Tsugaru Strait, crossing from the Sea of Japan to the Pacific Ocean. The Tianlangxing is the lone AGI vessel with the PLAN’s North Sea Fleet and the most likely vessel to venture as far as the waters off Alaska. Japanese authorities protested the AGI’s entry into Japan’s territorial sea during its transit of the Tsugaru Strait.
The United States, unsurprisingly, has not protested the PLAN vessel’s suspected surveillance of the coast and of the THAAD test as it was operating in international waters. U.S. officials told CNN that the vessel was operating approximately 100 miles off the Alaska coast, in international waters. The United States has long argued that, in accordance with international law, including the United Nations Convention on the Law of the Sea (UNCLOS), military vessels should be allowed to conduct surveillance and other activities in the exclusive economic zone (EEZ) of other states. The EEZ is defined by the convention as the area ranging for 200 nautical miles from the baselines of a coastal state.
The observation of the THAAD test by the PLAN vessel is not the first time that Chinese naval vessels have come to the Alaskan region. In 2015, five PLAN ships entered the Bering Sea and transited the Aleutian Islands lawfully, drawing a similarly measured reaction from the United States. More generally, in 2014, a Chinese Type 815 AGI surveilled activities at the Rim of the Pacific 2014 exercise, activity that was welcomed by Admiral Samuel J. Locklear III, then the commander of U.S. Pacific Command. Locklear noted that the action was “an acceptance by the Chinese of what we’ve been saying to them for some time, [which] is that military operations and survey operations in another country’s EEZs, where you have national — your own national security interest, are within international law and are acceptable.”
It’s unclear if the PLAN AGI specifically set out to Alaska in the second half of 2017 to monitor a suspected THAAD test. While the United States announced the test would come soon just days before it did, the first intercept test of THAAD against an IRBM-class target had long been baked into the Missile Defense Agency’s plan for this fiscal year. Accordingly, the vessel may have set out hoping to observe a test. Chinese sensitivities over THAAD’s technical capabilities are well-known given Beijing’s long-standing vociferous objection to the deployment of a THAAD battery on the Korean peninsula. The Chinese concern, however, is not with the interceptors, but the powerful X-band AN/TPY-2 radar that accompanies each THAAD battery.
Either way, the United States won’t be making an incident of the observation of this latest intercept test by a PLAN AGI 100 miles off the coast of Alaska. For Washington, preserving the U.S. Navy and Air Force’s ability to freely surveil China — in the air and on the surface within the EEZ — means tolerating that same behavior from the Chinese armed forces.