Japan’s incoming prime minister, Shigeru Ishiba, takes over next week with his eyes on an Asian NATO as a bulwark against Communist Chinese and North Korean threats. 

Mr. Ishiba, 67, elected president of the long-ruling Liberal-Democratic Party, who formally becomes prime minister on Tuesday, is sure to parlay his background as a former defense minister, on top of years as a member of the Japanese diet or parliament, into a cohesive proposal for a significant upgrade in Japan’s military role. 

Mr. Ishiba, viewed within his own party as a moderate and sometimes iconoclastic figure, signaled his desire for reforming what has been a Washington-led alliance structure well before his victory in the LDP election. 

Mr. Ishiba bases his call on what he called an “Asian version of NATO” on his observation of the war in Ukraine. It’s not  that NATO, led by Washington, rushed to Ukraine’s defense against Russia that inspired him. Rather, it’s that Ukraine is not a member of the alliance — and was therefore exposed to President Putin’s expansionist aims. 

“It is not hard to imagine that this prompted President Putin’s decision,” one of Japan’s major newspapers, the Asahi Shimbun, quoted him as remarking at a news conference on September 11. With that example in mind, reported Asahi, he stressed “the need to build a collective security system in Asia.”

Mr. Ishiba, who served as defense minister in 2007 and 2008,  faces other, perhaps more immediate priorities, including economic problems and scandals within the LDP, but is expected to want to expand the longstanding Japan-American alliance by merging it with other alliances, including the newly formed Aukus, the acronym for the grouping of Australia, the United Kingdom and the U.S.

He would have to move warily, however, if he expects South Korea, a strong American ally ever since the Korean War, to want to enter what might appear as an alliance with the country that ruled the Korean peninsula for 35 years until the end of World War II. 

Prime Minister Kishida, Japan’s outgoing leader, and President Yoon of South Korea agreed to cooperate closely in their meeting last year at Camp David, hosted by President Biden, but stopped well short of considering a trilateral alliance.

Mr. Ishiba also would want to build on Quad Four, the quadrilateral security dialog involving Japan, Australia, America and India, but that’s far from a military alliance. They simply discuss defense and economic issues while India remains “neutral,” wary of further antagonizing China, with which it’s fought a number of border skirmishes, and Russia, from which it imports vital arms, including aircraft.

Nor is the Japan-American alliance without problems. Like his predecessors, Mr. Ishiba will face heated opposition in Japan’s southernmost Okinawa prefecture against construction of a new base for American marine helicopters. Okinawans have staged numerous mass protests against the base, which has the support of the central government.

Before addressing these sensitive issues, Mr. Ishiba will focus on reforming and reunifying the fractious LDP. Asahi quoted him, in his victory speech, as praising Mr. Kishida for stepping down as LDP and national leader  “to regain the trust of the people so that the LDP can be reborn.”

Criticism, said Japan’s Kyodo news agency, has “swirled over a slush funds scandal that has eroded public confidence in the LDP, prompting calls for party lawmakers to make the flow of money more transparent.”