The Philippines Department of Foreign Affairs announced that China is seeking permission to conduct hydrographic surveys of the Benham Rise, an underwater plateau about 150 nautical miles to the east of the northern Philippine island of Luzon. Over the past month, a string of reports indicate that China may have already been surveying these waters without the permission of the Philippines, which has exclusive economic rights over the area. While survey activity may point to Chinese economic exploitation of the potentially resource-rich plateau, it could also indicate preparation for submarine operations in a future Western Pacific clash.
In early March the Philippines Defense Minister revealed that a Chinese survey ship was found in the rise. He further revealed that there had also been possible survey operations over a three-month period last fall and that the Philippines had sent China a dozen diplomatic protests over the issue.
The Philippines won U.N. recognition of Benham Rise as part of its continental shelf in 2012, granting it exclusive economic rights beyond the 200 nautical miles typically granted coastal states. Located some 150 nautical miles east of the Philippines, the area is not part of maritime disputes between China and the Philippines in the South China Sea. However, since reports of the Chinese survey ships resurfaced in March, the Philippines increased patrols efforts by its navy and coast guard to protect its claims over the region.Enjoying this article? Click here to subscribe for full access. Just $5 a month.
China’s reaction to the reports and accusation was surprisingly conciliatory and went to pains to highlight positive Sino-Filipino relations and make assurances that it had no designs on the rise. A spokesperson for China’s Ministry of Foreign Affairs said that, “the Chinese side fully respects the Phillippines’ rights over the continental shelf in the Benham Rise. There is no such thing of China challenging the Philippines’ rights.” She went on to assert that the survey vessel was exercising innocent passage and freedom of navigation consistent with the UN Law of the Sea and had not conducted survey activities in the area.
While circumstantial evidence that China has been surveying the area is strong, admitting to it would put China in a difficult position. If the surveying was for commercial exploitation, it would violate the Philippines’ economic rights that China says it recognizes. If the surveying was for military purposes, then it would weaken China’s position against similar surveys that the U.S. Navy conducts in the South China Sea, which China claims violate UN Law of the Sea prohibitions against certain military activities in other states’ exclusive economic zones.
Yet another possibility raised by the Philippines Defense Minister is that the surveys might also be to support Chinese submarine operations. The zone could play a critical role in a potential clash with the United States.
The Benham Rise is directly south of the eastern approaches to the Luzon Strait between Taiwan and the Philippines, which is the main access route from the Western Pacific Ocean to the South China Sea. In a conflict, control of that strait would dictate whether China’s South Sea Fleet could “break out” of the South China Sea into the Western Pacific to the waters between the first and second island chains, or if the U.S. Navy could move forces into the South China Sea to conduct its own combat operations.
The Center for Strategic and Budgetary Assessments envisioned what a U.S.-China clash might look like in this zone in its recent fleet architecture study for the U.S. Navy:
[Forces east of the first island chain] would be focused on attacking Chinese naval forces in the open ocean and conducting long-range strikes against Chinese forces and other targets in the South and East China Seas. U.S. allies would be expected to contribute ASW, SUW, ISR, and counter-ISR capabilities, particularly to ensure access through critical chokepoints [like the Luzon Strait], as well as land-based strike and AAW capabilities.
The study further recommends that, “Chinese submarines [outside the first island chain] would be attacked by additional P-8s flying from bases in Japan and the Philippines.” If China did intend to position submarines over the Benham Rise to threaten allied control of the Luzon Strait, they would be susceptible to detection by those Philippines-based U.S. P-8 sub-hunting aircraft. Detailed hydrographic information of the area would be critical to helping China’s submarines evade U.S. efforts to find them.
And Chinese surveys may have included other strategically sensitive areas. Before his March revelations, the Philippines Defense Minister said in February that Chinese survey ships have also been in the vicinity of Surigao, over 200 nautical miles south of Benham Rise. Winding through the middle of the Philippine archipelago, the Surigao Strait is one of the few alternate passages between the South China Sea (via the Sulu Sea) and the Western Pacific.
In World War II a squadron of Japanese battleships unsuccessfully tried to pass through the strait to surprise a U.S. fleet in Leyte Gulf, but were instead surprised by U.S. forces in the strait’s confined waters. If China also conducted survey operations near Surigao, it could have been in anticipation of the possibility that the U.S. or its allies might try the reverse and use the passage to move forces from the western Pacific into the South China Sea.
The acting Philippines Secretary of Foreign Affairs also told reporters that China refused the condition that an observer from the Philippines accompany the Chinese operations when it had requested permission to survey Benham Rise in the past. If China proceeded to conduct survey operations without the Philippines’ permission after requesting it over the observer condition, it supports the supposition that the surveys were for national security rather than economic purposes.
The United States also conducts hydrographic surveys. When China seized a U.S. Navy hydrographic Unmanned Underwater Vehicle (UUV) last December from the USNS Bowditch, a civilian-crewed hydrographic survey ship, it was widely speculated to be a ‘test’ of then President-elect Trump. The UUV had been collecting oceanographic data in the waters between the old U.S. Naval base at Subic Bay in Luzon and the Scarborough Shoal, site of an intense territorial dispute between China and the Philippines that could also embroil the United States. That at least raises the possibility that rather than a test of the incoming U.S. President, all China may have wanted to do is disrupt the U.S. Navy’s own survey efforts.