Tensions between the United States and China are rising in the lead-up to a ruling by the United Nations Permanent Court of Arbitration on a US-backed legal challenge launched by the Philippines to Chinese territorial claims in the South China Sea.

Last Wednesday, leading Republican and Democratic Party senators joined forces to introduce legislation, “The Asia-Pacific Maritime Security Initiative Act,” that is aimed at dramatically increasing the US intervention into the territorial disputes. The legislation authorises the Obama administration to give greater military assistance to the Philippines and other rivals to China’s claims, while requiring the White House report to the Senate on US plans for “freedom of navigation assertions” and “China’s activities in the South China Sea.”

The US has conducted two “freedom of navigation” operations, once in October 2015 and again in January, during which an American warship intruded into the 12-mile territorial zone around Chinese-held and claimed islands.

The tabling of the legislation was accompanied by strident condemnations of China over its reclamation of land from the sea around small islands and reefs, its construction of airstrips and docks and deployment of military forces and missile defence systems on territory that it controls.

Democratic Party Senator Ben Cardin denounced “China’s provocative actions in the South China Sea.” Republican Cory Gardner asserted that “China’s ongoing reclamation activities and militarisation of the South China Sea threatens regional stability and represents a clear and fundamental challenge to international law.”

Democrat Robert Menendez complained that “for too long, as China continues its aggressive and expansive policies, the United States has played the role of observer, or perhaps protestor, but not yet an actor.” The legislation, Menendez declared, would “send a signal to our friends and allies in the region that the international community—led by the United States—will no longer tolerate China’s efforts to militarise its foreign policy.”

These accusations of Chinese aggression turn reality on its head. The longstanding territorial disputes in the South China Sea have only emerged as major international issues—and the possible trigger for a catastrophic war—due to the US “pivot” to Asia to undermine China’s influence. Launched by the Obama administration in 2011, the pivot has involved the build-up of US military forces and activities in the region that threaten Beijing. China has made efforts to cement its grip over territory in the South China Sea, by reclamation and military deployments, largely been in response to Washington’s active encouragement of the Philippines and Vietnam to pursue their claims.

Hearings of senate committees last Thursday were used by various senators to grill representatives of the Obama administration and demand greater US military intervention in the South China Sea.

Opening the Foreign Relations Committee, at which Deputy Secretary of State Anthony Blinken was called to testify, Republican Bob Corker asserted: “We’ve reached a point now, where there’s no denying the fact that China has positioned itself as a geopolitical rival to the United States.” Calling for the navy to conduct a freedom of navigation operation inside Chinese-claimed territory “every week,” Corker declared: “Sending one a quarter is simply insufficient to send a strong message to China.”

In the Armed Services Committee, Senator John McCain, the 2008 Republican presidential candidate, lambasted Defense Secretary Ashton Carter and the Obama administration for classifying provocative US naval and aerial operations taking place in the vicinity of Chinese-held territory. Carter refused to provide details on reports that US A-10 Warthog attack aircraft have recently been flying from a base in the Philippines to the area near Scarborough Shoal—a small reef that is claimed by the Philippines but is effectively controlled by China.

Scarborough Shoal—known as Huangyan Island in China—is one of the disputed territories that the UN court has been asked by the Philippines to adjudicate on. The US Navy has alleged that Chinese survey ships have been operating in the area, and speculated that China may respond to a ruling in favour of the Philippines by deploying military forces onto the shoal and initiating land reclamation in order to expand it and allow for the construction of airstrips and other infrastructure.

Last week, the Chinese Defense Ministry stated: “Huangyan Island is China’s inherent territory and the Chinese military will take all necessary measures to safeguard national sovereignty and security.” It denounced the United States for “promoting militarisation of the South China Sea in the name of freedom of navigation.”

Bonnie Glaser from the US Center for Strategic and International Studies (CSIS) told the Wall Street Journal last week: “A political decision would have to be made that Chinese reclamation on Scarborough is unacceptable. But do we really want to draw a red line here? And what would the US do if the Chinese simply went ahead anyway?”

The rhetoric in the Senate reflects the fact that major figures in the US political establishment are more than prepared to trigger a war with China, using the territorial disputes as the pretext. During the recent joint US-Philippines’ Balikatan military exercises, American and Filipino troops rehearsed an amphibious assault to retake an island in the South China Sea that had been seized by an unspecified country.

For its part, the Chinese regime is ratcheting up tensions as well. On April 28, Beijing rejected a request by the US aircraft carrier USS John C Stennis and its support ships to make a port call at Hong Kong. The refusal is the first time in more than a decade that US warships have been denied entry into Hong Kong and only the third time since the territory was reincorporated into China in 1997.

Over the past week, Chinese foreign minister Wang Zi has engaged in top level talks with Russian foreign minister Sergey Lavrov to try and enlist Moscow’s support. Lavrov responded with a statement that “outside parties”—a clear reference to the US—“should not interfere” in the South China Sea disputes.

The prospect of an incident taking place is steadily increasing. Reuters reported on Saturday that the Chinese military is training thousands of fishermen as a militia to assist with “safeguarding Chinese sovereignty,” by gathering information and monitoring the movement on foreign ships. According to the report, some fishing crews have been issued with small arms.