SEOUL — America’s defense secretary, Pete Hegseth, threw down  the gauntlet before Communist China, warning Beijing that America “will be ready for war” if the People’s Republic persists in its bid to “become a hegemonic power.”

Mr. Hegseth, in his maiden address to the Shangri-la dialogue at Singapore before defense ministers and senior officials from upwards of 40 countries, put the Chinese on notice that they had better cease and desist from their bid for China “to become a hegemonic power” in the Indo-Pacific.

Mr. Hegseth’s remarks, at the annual gathering, sponsored by the International Institute of Strategic Studies at London, of some of the world’s most powerful military leaders set a tough tone in which he described President Trump as a “man of peace” dedicated not to “starting wars” but to “preventing them.”

The point was to give an impression of America’s military muscle in Asia while skimming over Europe and the Middle East — and avoiding Russia’s war in Ukraine other than to express relief that “our allies” were coming to “share the burden” for their own defense. Incredibly, he praised the North Atlantic Treaty members  as finally spending more on defense, leaving unstated the willingness of leading NATO nations, notably Germany, to increase their support for Ukraine in its war against Russia.

Mr. Hegseth, though, focused largely on Communist China, accusing the Chinese of just about everything from doing all possible to “steal technology” to seeking “to intimidate” others  to building bases in the South China Sea. Mr. Hegseth gave an impression of immediacy to his message, warning “the threat China imposes” was not only “real” but “could be imminent.” Lest anyone doubt the danger, he said, “we are not going to sugarcoat it.”

He came close to declaring that Mr. Trump would be ready to go to war if the Chinese party boss, President Xi, dared try to take over the island democracy of Taiwan. “Any attempt by China to conquer Taiwan,” he warned, “will have devastating consequences.”

Without saying exactly what, he said “the United States does not seek war, but we will not be reckless.” Ultimately, he said, “We must be sure China cannot dominate us.”

Mr. Hegseth embellished his remarks with praise for rising cooperation with America’s allies, ranging from Japan to the Philippines to Australia. He also cited India as a bulwark of the Quad, a grouping of America, India, Japan, and Australia that’s not a military alliance but cooperates, he said, on all-important “logistics networks” and “Indo-Pacific industrial resilience.”

Mr. Hegseth’s remarks, besides avoiding Ukraine and Israel’s war against Hamas, omitted one important Asian ally that’s widely regarded as just as important as Japan. That’s South Korea, where 28,500 American troops stand guard against North Korea, an ally of both Communist China and Russia.

The defense secretary  used the word “Korea” just once, Seoul’s Yonhap News, noted when he criticized “key allies and partners in Asia” for spending “less on defense in the face of an even more formidable threat — not to mention North Korea.”

An obvious excuse for Mr. Hegseth’s avoidance of Korea is that South Koreans are voting for a new president amid bitter political turbulence. Koreans have been casting ballots in advance of the election day Tuesday, after which they will know if the leftist Lee Jae-myung takes over as widely forecast from the present conservative government. An acting president is now at the helm in place of Yoon Suk-yeol, impeached and ousted for attempting to impose martial law on December 3.

Mr. Hegseth had nothing to say about ignoring South Korea, but he did note “We are here this morning, and somebody else isn’t.” That was a reference to China’s defense minister, Dong Jun, who skipped the confab — presumably not wanting to hear for himself, in person and first-hand, what Mr. Hegseth had to say.