BEIJING — Only a day before a small Chinese boat sidled up to a United States Navy research vessel in waters off the Philippines and audaciously seized an underwater drone from American sailors, the commander of United States military operations in the region told an audience in Australia that America had a winning military formula.

“Capability times resolve times signaling equals deterrence,” Adm. Harry B. Harris Jr. told a blue-chip crowd of diplomats and analysts at the prestigious Lowy Institute in Sydney, the leading city in America’s closest ally in the region.

In the eyes of America’s friends in Asia, the brazen maneuver to launch an operation against an American Navy vessel in international waters in the South China Sea about 50 miles from the Philippines, another close American ally, has raised questions about one of the admiral’s crucial words. It was also seen by some as a taunt to President-elect Donald J. Trump, who has challenged the One China policy on Taiwan and has vowed to deal forcefully with Beijing in trade and other issues.

“The weak link is the resolve, and the Chinese are testing that, as well as baiting Trump,” said Euan Graham, the director of international security at the Lowy Institute. “Capability, yes. Signaling, yes, with sending F-22 fighter jets to Australia. But the very muted response means the equation falls down on resolve.”