LONDON — Prime Minister Kishida will be selling President Biden on Japan’s new defense strategy, including its large increase in spending on its small “Self-Defense Forces,” when they meet Friday at the White House.

Mr. Kishida, in his first visit to Washington since becoming prime minister in September 2021, is sure to discuss Japan’s plans to double the military budget over the next five years, to 2 percent from 1 percent of the country’s GDP, which crested at $4.3 trillion last year, the world’s third largest after America and China. Japan is spending nearly $40 billion for its euphemistically named Self-Defence Forces for the fiscal year ending in March.

Mr. Kishida’s Washington visit climaxes five days of summits with allied leaders, including Britain’s prime minister, Rishi Sunak, with whom he signed a historic agreement Wednesday under which they’ll post troops in each other’s countries. 

Mr. Sunak said the agreement, signed at the Tower of London, shows “a shared outlook on the world, a shared understanding of the challenges we face, a shared ambition to use our place in the world for good.” (The agreement needs approval by Britain’s parliament and the Japanese diet or national assembly.)

Japan’s Nikkei Asia, an offshoot of the financial paper Nihon Keizai Shimbun, quoted Zack Cooper of the American Enterprise Institute as calling the deal “a real effort by Japan to build out its partnerships, not just in a U.S. alliance context, but in a number of bilateral and even trilateral relationships.”

Mr. Kishida, in the run-up to his summit with Mr. Biden, has seen  the leaders of France and Italy as well as Britain, and is meeting Canada’s prime minister, Justin Trudeau, on Thursday before taking off for Washington. 

It’s Japan’s alliance with America that counts by far the most, though, and Japan’s foreign and defense ministers are closeted Wednesday with their American counterparts, Secretaries Blinken and Austin, at which they’re explaining in detail Japan’s expanding defense plans.

In all the talks, Mr. Kishida’s overriding concern is China’s rising military influence as seen in the Chinese president’s threats against the independent off-shore island province of Taiwan. Mr. Kishida is also worried about the claims of the North Korean leader, Kim Jong-un, that he now has tactical nuclear warheads that his intermediate-range missiles can deliver to targets in Japan and South Korea.

“If China would be the main problem, Japan will be the main enemy,” Bonji Ohara of the Sasakawa Peace Foundation said. “Cooperation between the United States, the only ally with Japan, is fundamental.”

Mr. Ohara, in a forum under the aegis of the Center for Strategic and International Studies at Washington, said China had motivated Japan to consider rising threats to security. Japan has 250,000 troops in its Self-Defense Forces and is constrained by Article 9 of its post-war constitution, promulgated during the American occupation under General Douglas MacArthur, not to wage war or send troops overseas.

“China did not want the international community to be unified,” Mr. Ohara said. “China always has tried to divide countries. They want the allies of the U.S. to keep distance from the U.S.” 

“China has tried to increase its nuclear warfare,” he warned, “The U.S. needs to deter not only Russia but China.”

Also at the CSIS forum, Kori Schake of the American Enterprise Institute warned against being fooled by China’s vows of “no first use” of nuclear weapons. “Pledges of ‘no first use’ sound nice,” she said. “They just don’t have any credibility.”

American and Japanese officials are getting down to nitty-gritty details of defense in meetings today and tomorrow. The defense department press secretary, Brigadier General Pat Ryder, stuck to generalities, saying they would discuss “our shared vision of a modernized alliance.”

More specifically, the Associated Press reported officials as saying the 12th Marine Regiment on Okinawa would be configured into “the 12th Marine Littoral Regiment,” making it able to respond rapidly to regional threats. About 55,000 American troops are stationed in Japan, more than half in the southern Japanese prefecture of Okinawa, including about 20,000 Marines.

The reason for making the 12th Marine Regiment more capable of moving quickly into action clearly relates to Taiwan. The Chinese have been staging air and naval exercises, sending planes into Taiwan’s Air Defense Identification Zone. Messrs. Biden and Kishima are sure to reaffirm their “commitment” to defense of the region. 

This time, though, Mr. Kishima is expected to get into much more detail on Japan’s strategy — a step beyond previous Japanese defense aims, though Japan is still not announcing plans to increase the number of  “Self-Defense” troops.