Tensions are rising again between the Philippines and the People’s Republic of China (PRC) over rival claims to small islands and their surrounding waters in the South China Sea. The latest incident began in late March when more than 200 Chinese “fishing vessels” arrived at Whitsun Reef, which Manila calls Juan Felipe Reef – a maritime structure that it insists lies located within the country’s 200-mile exclusive economic zone. The Chinese ships have continued to linger, supposedly because of rough seas caused by adverse weather conditions.

Philippines’ Defense Secretary Delfin Lorenzana scorned that explanation, noting that the weather had been fine throughout most of the period. He also challenged the official status of the ships as fishing vessels, charging that they were manned by armed militias. “The continued presence of Chinese maritime militias in the area reveals their intent to further occupy (areas) in the West Philippine Sea,” Lorenzana said in a statement, using Manila’s name for the South China Sea. The Philippines government also responded to the presence of the ships by sending fighter planes to shadow the fleet.

The United States has quickly injected itself into the dispute. Secretary of State Antony Blinken emphatically took Manila’s side in a statement on Twitter. “The United States stands with our ally, the Philippines, in the face of the PRC’s maritime militia amassing at Whitson Reef,” he stated, emphasizing that. “We will always stand by our allies and stand up for the rules-based international order.” Anti​war​.com analyst Dave DeCamp notes that in an earlier telephone call with Philippines’ Foreign Affairs Secretary Teodoro Locsin Jr., Blinken emphasized Washington’s solidarity with its longtime treaty ally, including on the South China Sea territorial disputes. Indeed, he “made it clear that any incident between the Philippines and Beijing in the South China Sea could bring the US into war. According to a readout of the call, Blinken ‘stressed the importance of the Mutual Defense Treaty for the security of both nations, and its clear application to armed attacks against the Philippine armed forces, public vessels, or aircraft in the Pacific, which includes the South China Sea.’” One regional observer, Mark J. Valencia, a scholar at the National Institute of South China Sea Studies in Haikow, China, accuses the Biden administration of outdoing even its predecessor in terms of “bluff and bluster” regarding the South China Sea.

The Biden administration’s position certainly is unwise and potentially dangerous. Apparently confident of U.S. military backing, the Philippines government is taking a tough stance against its much larger, more powerful neighbor. Aides to President Rodrigo Duterte warned Beijing on April 5 that the continued presence of PRC ships at Whitsun Reef would damage bilateral ties and even lead to “unwanted hostilities.” Presidential spokesman Harry Roque bluntly told a news conference: “We will not give up even a single inch of our national territory or our exclusive economic zone (EEZ).” It is unlikely that a tiny country like the Philippines would be so bold if it did not assume that it had the powerful US military in its corner. Washington is giving Manila every reason to make that assumption. The United States has now deployed an aircraft carrier strike group in the South China Sea as tangible evidence of support for its ally.

Flirting with an armed clash with China would be imprudent even if the United States had significant interests at stake in the territorial dispute between the Philippines and the PRC. But the involvement of genuine American interests in that quarrel is minimal at most.

As a general matter, it is a very bad idea to encourage small allies or clients to take a jingoistic stance against a much larger, more powerful adversary. Indeed, it’s a textbook example of creating a situation in which a volatile client state can drag its patron into an unwanted and utterly unnecessary war. The most tragic historical example of that process is how Russia’s support for Serbia in 1914 encouraged Belgrade to defy Austria-Hungary’s demands following the assassination of Archduke Franz Ferdinand by a Serbian nationalist. Since Imperial Germany, the single strongest country in Europe, was backing Vienna’s demands, the stage was set for a war that engulfed the continent and killed millions.

A war between the United States and China likely would be at least that bad. Taking such a risk over even important issues is questionable enough. Doing so to support a small client state, and one headed by the notoriously volatile Rodrigo Duterte, over a petty territorial squabble would be the operational definition of irresponsible. The Biden administration needs to back away from its ally’s claims and make it very clear to Manila that the United States is not going to risk a war with the PRC over such stakes.