Though it rarely makes headlines in the US, the simmering rivalry between American and Chinese military forces has prompted some to declare the South China Sea - where Beijing has been building out its military and naval infrastructure in defiance of international court rulings - the "world's most dangerous hotspot".

And as China has transformed rocky atolls into stationary aircraft carriers, nobody has been more vocal about the dangers of China's increasingly aggressive posture in the Pacific than Admiral Philip Davidson, the commander of U.S. Indo-Pacific Command, who has warned about the growing geopolitical threat even as many established economists have played down the risk of a conflict because, in theory, the economic links between the world's two largest economies represent a reliable counterweight.

Admiral Philip Davidson

Offering yet another ominous warning just days after Washington again provoked Beijing by flying two B-52 bombers over the contested sea, Davidson told a group of reporters that he had observed a rise in Chinese military activity in the Pacific.

Asked about the US's "freedom of navigation" operations in the region, Davidson declined to offer specifics but said only that the US would remain "an enduring Pacific power." But turning the focus again to China, Davidson warned that China's military buildup was a "hazard" to trade flows and financial information that circulates via fiber optic cables running on the ocean floor under the South China Sea.

"It’s building, it’s not reducing in any sense of the word," Davidson told reporters on Thursday in Singapore when asked about China’s military activities in the South China Sea. "There has been more activity with ships, fighters and bombers over the last year than in previous years, absolutely." "It’s a hazard to trade flows, the commercial activity, the financial information that flows on cables under the South China Sea, writ large,” Davidson added.

As Bloomberg pointed out, Davidson's comments appeared to assuage US allies' concerns about a possible US pullout from the region, which have intensified thanks to President Trump's isolationist rhetoric.

Davidson’s comments are the latest from a senior U.S. official seeking to reassure allies in Southeast Asia of the American commitment to what Washington refers to as the Indo-Pacific region. Secretary of State Michael Pompeo last week in Manila assured the Philippines that a defense treaty would apply if its vessels or planes are attacked in the South China Sea.

However, many of the US's regional allies, particularly the Philippines, have questioned whether the US has done enough to curb Beijing's ambitions. Some top Philippine military officials have even questioned whether the US defense pact needs to be changed.

Top Philippine officials have clashed over whether the mutual defense pact with the U.S. needs to be changed. While Foreign Secretary Teodoro Locsin has said the 1951 accord should stay the same, Defense Secretary Delfin Lorenzana wants it reviewed, even after Pompeo’s assurances. The U.S. hasn’t stopped Chinese “aggressive actions” so far, Lorenzana noted in a statement earlier this week, while warning that vagueness in the document could cause “chaos during a crisis” and that the Philippines didn’t want to be dragged into a shooting war it didn’t start. China has targeted a 7.5% increase in defense spending in 2019, a slowdown from last year’s projected 8.1% increase though still seen as consistent with President Xi Jinping’s plans to grow and advance the military.

And even with domestic growth slowing, China continues to spend on its military buildup. And Davidson doesn't expect this to change. And Beijing's increasingly belligerent rhetoric about its plans for "reunifying" with Taiwan would seem to confirm this assessment.