As China consolidates its hold in South China Sea and wields its military, economic and diplomatic leverage, smaller countries see no credible option but to work with Beijing, even if that means furthering Chinese objectives. Manila, for example, seems willing to accede to Beijing's demand for joint development of hydrocarbon resources in the Philippines' own exclusive economic zone.
The plain fact is that U.S. inaction under successive administrations has allowed China to gain effective control over a strategic sea that is more than twice the size of the Gulf of Mexico and 50 percent bigger than the Mediterranean Sea. Australia's Kevin Rudd, who is still fending off accusations that he was "a slavish pro-China prime minister," has acknowledged that "Chinese policy has not yet been challenged in the South China Sea by the United States to any significant extent."
The U.S., even at the risk of fostering Philippine helplessness against Chinese expansionism, has refused to clarify whether its 1951 Mutual Defense Treaty with Manila would apply to an attack on Philippine troops or vessels in the South China Sea. This refusal stands in contrast to Washington's commitment to the defense of the Japanese-administered but Chinese-claimed Senkaku Islands in the East China Sea. U.S. President Donald Trump, in his joint statement with Prime Minister Shinzo Abe in April, said that "Article 5 of the U.S.-Japan Treaty of Mutual Cooperation and Security covers the Senkaku Islands."