America’s neophyte defense secretary, Pete Hegseth, on Saturday is sure to address the need to stand up to Communist China.

At the so-called Shangri-La Dialogue in Singapore, Mr. Hegseth won’t have to engage in fire-eating rhetoric when he speaks to many of the world’s top defense officials to convey the sense that China is public enemy no. 1 in Washington’s evolving Indo-Pacific strategy. 

Mr. Hegseth has already signaled the priority when he ranked “deterring China in the Indo-Pacific” right after “defense of the U.S. homeland” while directing his undersecretary of defense, Elbridge Colby, to come up with a new “National Defense Strategy.”At the top of concerns lies the fear that China’s president, Xi Jinping, may go beyond bullying Taiwan with air and naval exercises and attempt to take over the independent island province.

The drama of Mr. Hegseth’s remarks, though, likely won’t be as intense as it could be, as he’ll be unable to look at China’s defense minister, Dong Jun, for signs of a response. China for the first time in five years is not elevating the Shangri-La Dialogue to ministerial level, opting instead to send a “delegation from the National Defense University.” Thus there will be no chance for Mr. Hegseth to engage one-on-one with his counterpart as did the previous American defense secretary, Lloyd Austin, at last year’s Shangri-La. 

In response to Mr. Hegseth’s message, the Chinese, by staying away, are sending a message of their own. China’s English-language propaganda paper, Global Times, seemed to be enjoying the speculation by quoting a man identified as a “senior fellow” at one of its leading think tanks, Zhou Bo, as saying the decision “should not be overinterpreted.”

Considering that Mr. Hegseth, when he ordered the strategy review, named no other nation — friend or foe — there was no doubting the importance with which Washington views China in comparison with other flashpoints, including Russia as it conducts its war with Ukraine.

As a corollary to the emphasis on China, Mr. Hegseth hinted at pulling several thousand troops from South Korea and Japan by saying the new strategy would “prioritize increasing burden-sharing with allies and partners around the world.” South Korea is now contributing $1.1 billion annually toward the costs of keeping America’s 28,500 troops on bases in Korea, but President Trump believes Seoul should pay much more.

Moreover, by singling out Mr. Colby by name, Mr. Hegseth showed he agrees with the undersecretary’s warnings of the need for America to shore up defenses against China — and for both Taiwan and South Korea to do more on their own. At Senate hearings in March, Mr. Colby said that the loss of Taiwan would be “an incredible disaster” and that Taiwan should invest 10 percent of its gross domestic product in defense.

Mr. Colby has aroused greater concerns in South Korea by saying that American forces might deploy from Korean bases if needed to battle China, leaving the South Koreans to face the North alone. The inference is that American bases in South Korea could support a war for Taiwan — a view that Seoul opposes for fear of upsetting Beijing.

The commander in Korea, General Xavier Brunson, hinted at the need for such flexibility when he remarked, in a Zoom conversation, that “Korea is in a dynamic environment” and, “should other missions be mentioned, I will do those things I am asked to do.”

While repeatedly pronouncing Americans and Koreans “in lockstep” over defense policy, however, the alliance partners are out of synch for one other reason. 

Messrs. Hegseth and Austin both avoided Seoul during visits to Japan. Washington wanted to sidestep the political crisis triggered by the abortive martial law decree issued on December 3 by the man who was then Korea’s president, Yoon Suk-yeol, since then impeached, ousted and now on trial for “insurrection.”

Washington undoubtedly will look for contact with the new president to be elected in a “snap election” on Tuesday. The winner probably will be the leftist Lee Jae-myung. He has said he supports the status quo, but that has yet to be proven as the alliance faces one of its greatest tests regardless of what Mr. Hegseth says in Singapore.

In the meantime, Korea, like China, did not send a defense minister to the Shangri-La. The previous defense minister is in jail for his role in the martial law fiasco, and the acting defense minister decided to stay away. Instead, Seoul’s deputy defense minister is representing Korea — though he is unable to make any commitments and is sure to be out of a job very soon.