Communist China’s president, Xi Jinping, is picking up where Mao Zedung left off before dying in 1976, asserting China’s power over the land the Chinese-armed Khmer Rouge years earlier had turned into “the killing fields.”

Nearly half a century since the Khmer Rouge rampaged across Cambodia in a campaign of wanton killing for which China provided the arms, Mr. Xi was in the capital city of Phnom Penh embracing the latter-day leaders whom Beijing still arms and aids.

“Together We Strive, Together We Thrive,” signs greeting Mr. Xi read, according to China’s propaganda paper, Global Times. “Toward a Stable and Sustainable China-Cambodia Community with a Shared Future in the New Era”: That was the theme of the visit that capped off Mr. Xi’s foray into Southeast Asia after an initial stop at Hanoi, capital of Vietnam, armed and equipped by China for the conquest of the American-backed “South” Vietnam half a century ago.

In the convoluted history of the country and the region, the Communist Vietnamese drove the Khmer Rouge out of power in 1979 after they’d killed about two million people since their victory over an American-backed regime that collapsed on April 17, 1975, after the Americans had stopped providing arms and air support. The Chinese remained the staunch ally of the Khmer Rouge throughout their reign of terror until the Communist Vietnamese drove the KR out, replacing them with leaders who, after many twists and turns, are again kowtowing to Beijing.

Nobody was harking back to that awful era, though, as Mr. Xi embraced Cambodia’s latter-day leaders, who have survived as the sons of the leaders who ruled the country decades ago. Without mentioning their illustrious fathers, Mr. Xi overflowed with confidence “in national development with the blessing of King Sihamoni and under the leader of the government headed by Prime Minister Hun Manet.”

Nobody needed reminding that King Norodom Sihamoni’s father, King Norodom Sihanouk, descendant of a royal family dating from the French colonial era, had handed him the throne 21 years earlier. Totally forgotten was that the first King Sihanouk, who then was “Prince Sihanouk,” had found a home in North Korea after a pro-American, anti-Communist regime took over in 1970 when he was visiting Moscow looking for Soviet support. The North Koreans even built him a palace fit for royalty — a payoff for the friendship he had formed earlier with the founder of the North Korean ruling dynasty, Kim Il-sung.

Nor was it necessary to mention that Hun Manet had been appointed as head of the government by his father, Hun Sen, a one-time member of the Khmer Rouge who had taken charge of Cambodia from the time the Vietnamese had driven out the Khmer Rouge in 1979. Not that Hun Sen had disappeared: He remains president of the senate, a body of yes-men that does whatever it’s told, and in that capacity was on Mr. Xi’s agenda for a personal conversation. 

Mr. Xi, from the moment he arrived aboard the Chinese presidential plane, a Boeing 747 that had carried him first to Hanoi and then Kuala Lumpur, was all about showing off Cambodia’s place in China’s “Belt-and-Road strategy” linking countries and ports in a network extending around Asia and to the Middle East. 

In Cambodia, the port is a naval base at Ream on the southern coast through which Hanoi once shipped Chinese-made arms for its forces in “South” Vietnam, with the blessing of Prince Sihanouk, during the Vietnam War. “Together, the two countries have shared the rough times and the smooth and consistently supported each other in times of need,” he said, according to the transcript in English.

Just as important, Mr. Xi framed his remarks as a none-too-subtle swipe at America for jacking up interest rates in a tariff and trade war that has stoked tensions with Washington.  

“Together we must stand against hegemonism, power politics and camp-based confrontation,” he said, according to the transcript. “We should advocate an equal and orderly multipolar world and a universally beneficial and inclusive economic globalization … jointly oppose protectionism, and defend an international environment of openness and cooperation” — qualities for which China has not been noted in its dealings with other countries, notably America.