President-elect Trump could soon enter office with a crisis afoot in Asia on account of an extraordinary show of force from the People’s Republic of China against the free Republic of China. Taipei’s Defense Ministry on Tuesday disclosed that it had detected around 90 Communist Chinese vessels and 53 military planes, the largest such armada in decades. This surge of Beijing’s forces in the Taiwan Strait and Western Pacific amounts to a test for Trump.

A top military intelligence official, Lieutenant General Hsieh Jih-sheng, said at a press conference that an “astonishing” number of Chinese vessels have been deployed at a scale that “could block external forces.” He added that “The message they are sending is very simple: The Taiwan Strait is ours.” The latest belligerence comes after the Republic’s president, Lai Ching-te, undertook an overseas trip to Guam and Hawaii. That appears to have infuriated Beijing.

Free China’s leaders are sounding the alarm that Beijing is now at work building “two walls” around the island. The first is just off Taiwan, and the second further out past the first island chain — the archipelago that comprises Japan, Taiwan, and part of the Philippines. Rather than a protective “boiling moat” around Taiwan, Communist China is building a vise. Free China’s foreign ministry calls Beijing a “troublemaker.”     

General Hsieh reckons that Beijing is “sending a very simple message” — their intent to make the Taiwan Strait an “internal sea” of mainland China. President Xi hardly appears worried that President Biden’s lame duck administration will impose costs on this adventurism. Eyes now swivel to the new American president. The Republic of China’s envoy at New York, Tom Chih-chiang Lee, tells us that his nation “looks forward to working closely” with Trump.

Where does Trump stand? The Journal asked him in October if he would “use military force against a blockade on Taiwan.” The president-elect responded in respect of Mr. Xi that “I wouldn’t have to, because he respects me and he knows I’m f— crazy.” He added that if Beijing moves against Taiwan, it can expect tariffs “at 150% to 200%.” Meanwhile, Taipei on Wednesday demanded that the “Beijing authorities immediately stop military intimidation.”

Candidate Trump in July told Bloomberg News that “Taiwan should pay us for defense.” That approach appears to have paid dividends in Europe, but Mr. Xi’s increasingly expansionist rhetoric makes the question more urgent in the Pacific. One observer, Matthew Pottinger, argues that Free China requires “a new military culture.” Or rather, a recovery of an old one — its late leader Chiang Kai-shek called his country a “citadel of freedom.”

On Sunday, President-elect Trump told “Meet the Press” that in respect of a Communist Chinese invasion “I’d prefer that they don’t do it. I have a very good relationship with President Xi. We have been communicating with each other.” Meanwhile, a spokeswoman for Beijing ventures that the mainland is “highly vigilant to the trend of separatist Taiwan forces colluding with external forces.” So the time of testing for President Trump could be sooner than we think.