Your Wednesday Briefing

We’re covering President Biden’s bid to reassure allies at the U.N. and new data on Johnson & Johnson’s vaccine booster.

Biden makes his U.N. debut

President Biden delivered his first address to the annual gathering of world leaders at the U.N. in New York City amid strong doubts about his ability to restore U.S. global leadership after the Trump administration’s “America First” isolationism.

Biden called for unity among allies in confronting the coronavirus pandemic, emerging technological threats and the rise of autocratic nations such as China and Russia.

“Our security, our prosperity and our very freedoms are interconnected, in my view, as never before,” Biden said. Asking the world to make the use of force “our tool of last resort, not our first,” he defended the U.S. withdrawal from Afghanistan.

President Xi Jinping of China, speaking later in the day via prerecorded video, rejected the American portrayal of his government as authoritarian and expansionist. He asserted that democracy is “not a special right reserved to an individual country.” Xi also said China won’t build more coal plants abroad.

The U.N. secretary general, António Guterres, warned in a sobering speech that nations needed to work together to confront the threats posed by war, climate change and the pandemic — “the greatest cascade of crises in our lifetimes.” He expressed fears about competition between China and the U.S. “Instead of the path of solidarity,” Guterres said, “we are on a dead end to destruction.”

Context: There is growing frustration with his administration’s diplomacy. The president’s refrain that the world must choose between democracy and autocracy looks different now that the Taliban are in control of Afghanistan. France has recalled its ambassador in a major diplomatic dispute over Biden’s decision to help Australia deploy submarines.

Lineup: China’s leader, Xi Jinping, will speak later today via a prerecorded video. President Jair Bolsonaro of Brazil, who is not vaccinated, defended the use of ineffective drugs to treat Covid-19. BTS performed yesterday, and a million viewers tuned in to watch the livestream.

In a clinical trial, the second dose delivered 94 percent efficacy against mild to severe Covid-19 in the U.S., up from 74 percent conferred with a single shot, the company reported. And two shots showed 100 percent efficacy against severe disease, although that estimate had a wide range of uncertainty.

The data, presented in a news release, has been submitted to U.S. drug regulators. The one-dose J. & J. vaccine, which can be easily stored, has been authorized for use in 65 countries worldwide.

Here are the latest updates and maps of the pandemic.

In other developments:

Will the submarine deal fuel an arms race in Asia?

As China swells into a military superpower, India, Vietnam and Singapore are spending more on defense. Japan is leaning to do the same.

Now Australia’s deal with the U.S. and Britain to develop long-range nuclear-powered submarines has catapulted the military contest with Beijing in Asia into a tense new phase.

The deal could accelerate an Asian arms buildup long before the submarines enter service — probably 10 years from now. China, which responded with anger to the news, may step up its military modernization. Other big spenders like India and Vietnam could accelerate their own weapons plans as well.

Countries trying to stay in the middle, like Indonesia, Malaysia and others, face a more volatile region and growing pressure to choose between Washington and Beijing.

Quotable: “The worry is that this will spark an untimely arms race, which the region does not need now, nor in the future,” said Dino Patti Djalal, a former Indonesian ambassador to the U.S.

THE LATEST NEWS

News From Asia

Spain liberalized its abortion laws in 2010. But many physicians in the country call themselves “conscientious objectors” and refuse to perform the procedure, often forcing women to travel long distances for one. Most public hospitals don’t offer abortions. The situation there offers a window into what awaits other countries.

Your guide to culture this fall

Navigate the new season across the arts world with help from Times critics and writers. They rounded up previews of what to watch, listen to and see this fall.

Music: 66 upcoming albums, concerts and festivals, featuring highly anticipated returns (Abba, Diana Ross) and collaborations (Lady Gaga and Tony Bennett).

Movies: A list of more than 125 upcoming films, including blockbusters (“Dune,” “No Time to Die”), art house hopefuls (“Spencer,” “Flee”) and everything in between (“The Many Saints of Newark”).

Television: 31 shows to watch — expect a lot of reboots.

Theater: Three new plays in experimental styles test Broadway’s possibilities.

PLAY, WATCH, EAT

What to Cook

This Japchae, teeming with savory flavors and contrasting textures, can be enjoyed during the Chuseok holiday.