North Korea, India, Chicago: Your Tuesday Briefing

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Good morning,

We start today with the U.S.-North Korea summit meeting, details of Michael Cohen’s coming congressional testimony, and today’s House vote on President Trump’s national emergency declaration.

Leaders arrive for U.S.-North Korea meeting

President Trump landed in Hanoi, Vietnam, today for his second summit meeting to discuss denuclearization with the North Korean leader, Kim Jong-un.

Tensions eased dramatically after the two leaders met last year, although the North has not taken substantial steps since then toward giving up its nuclear arsenal. Here’s what’s at stake when their two-day meeting begins Wednesday.

Go deeper: Vietnamese officials have suggested that North Korea could benefit from their approach of holding China at bay while courting the U.S., a former enemy.

A split screen for President Trump

As the first day of Mr. Trump’s meeting with Kim Jong-un ends, his former personal lawyer, Michael Cohen, is set to testify publicly against him in Congress.

The White House has shrugged off the clashing narratives. “I don’t think the president has any concerns whatsoever about Michael Cohen,” Sarah Huckabee Sanders, the White House press secretary, said last week.

The details: Mr. Cohen plans to portray his former client in starkly negative terms, according to a person familiar with his intended testimony. Using documents to support his claims, Mr. Cohen plans to describe what he says was Mr. Trump’s use of racist language, lies about his wealth and possible criminal conduct.

India strikes Pakistan, but leaders don’t rush to war

For the first time in five decades, Indian warplanes crossed into Pakistan today and launched airstrikes, escalating tensions between the nuclear-armed neighbors.

India said that it had struck a training camp for a militant group that claimed responsibility for a suicide attack that killed at least 40 Indian troops in the disputed territory of Kashmir this month. The country’s Foreign Ministry said a “very large number” of militants had been killed in the airstrikes.

Response: Pakistan said the strikes had done little damage, and Prime Minister Imran Khan dismissed them as an effort by his Indian counterpart, Narendra Modi, to shore up his popularity ahead of elections.

U.S. increases pressure on Venezuela’s leader

Vice President Mike Pence escalated the Trump administration’s efforts to pressure President Nicolás Maduro to step down, announcing additional sanctions on Monday and warning of more punitive measures.

Mr. Pence, who met with Venezuela’s opposition leader, Juan Guaidó, in Colombia, also warned countries in the region, particularly Mexico and Uruguay, that they could not remain neutral in the crisis.

Related: Jorge Ramos, a news anchor for Univision, said he was detained by the Venezuelan government after an interview with Mr. Maduro on Monday in Caracas.

If you have 12 minutes (maybe more), this is worth it

Have dark forces been messing with the universe?

The universe seems to be expanding far more rapidly than it should be. Astrophysicists have struggled to account for the discrepancy. They’ve been coming up with new ideas, which, if borne out, could mean rewriting the story of the origin of the cosmos, and its ultimate fate.

Our science reporter Dennis Overbye, who has a physics degree from M.I.T. and a way with words, explains.

Here’s what else is happening

New Brexit concession: Prime Minister Theresa May has accepted that Parliament should have the chance to delay Britain’s exit from the European Union if it rejects her withdrawal plan.

Worries over border action: The Democratic-led House is expected to vote today to reject President Trump’s declaration of a national emergency on the Mexican border. Republican defections could give the resolution momentum in the Senate.

Snapshot: Above, a scene from this year’s Kumbh Mela in India, a Hindu pilgrimage that is the largest religious gathering in the world. Critics say the once-humbling event has become too luxurious and corporate.

A soccer pro at 13: Olivia Moultrie said Monday that she had signed with an agent and with Nike, giving up the college scholarship she had accepted at 11.

Late-night comedy: Conan O’Brien was troubled by the improved ratings for an Oscars broadcast that lacked a host: “All last night I was like tossing and turning. ‘End of hosts. No host! Hosts gone!’”

What we’re listening to: This NPR report. Gina Lamb, a special sections editor, writes: “If you need a little break from political scrambling, try this story about political gambling — in Denmark, where you can bet on when an election will actually happen.”

Cook: This spicy lamb ragù comes together in 45 minutes but tastes like it took much longer. (Our Five Weeknight Dishes newsletter has more recipe recommendations.)

Watch: Many Oscar-winning films are available to stream at home.

See: Madeleine George’s play “Hurricane Diane,” at New York Theater Workshop, sees the god Dionysus trying to convince the women of Monmouth County, N.J., that the ecological end is near.

Listen: Norah Jones’s “Just a Little Bit” “leans toward jazz and Minimalism, with the meticulous Brian Blade on drums carrying a syncopated pulse as Jones sustains a drone on organ,” writes Jon Pareles.

Smarter Living: If you want to reduce your impact on the planet, look to your closet. Water and chemicals are used to dye and finish cotton clothes, and polyesters and nylons aren’t biodegradable. In this age of fast fashion, it’s best to wear your clothes for a long time. (Buying secondhand helps, too.)

Also, take our test to find out which health care policy aligns with your values.

And now for the Back Story on …

The Oxford comma

We often ask readers for Back Story ideas. Susanne Fischer of New York suggested the Oxford comma, which was traditionally used at Oxford University Press.

“I’m a big fan, use it often, and think it’s really important for clarification,” she wrote.

The Times, like most other news organizations, does not usually use the comma, which is also known as the serial comma. “In general, do not use a comma before and or or in a series: The snow stalled cars, buses and trains,” our stylebook says.

“A goal of punctuation is to make a sentence as clear as possible, and in most cases that final comma isn’t necessary for understanding the relationship of all the items in a series,” said Susan Wessling, The Times’s senior editor for editing standards.

There are exceptions. Around this time last year, a Maine dairy company agreed to pay its drivers $5 million after a dispute that hinged entirely on the lack of an Oxford comma — in a list of activities that did not require overtime payments.

That’s it for this briefing. See you next time.

— Chris

Thank you
To Eleanor Stanford and James K. Williamson for the break from the news. Inyoung Kang, a home screen editor based in London who often contributes to the briefings, wrote today’s Back Story. You can reach the team at briefing@nytimes.com.

P.S.
• We’re listening to “The Daily.” Today’s episode is about “Green Book,” the Oscar winner that critics say oversimplifies race relations.
• Here’s today’s mini crossword puzzle, and a clue: Author of the “Odyssey” and the “Iliad” (5 letters). You can find all our puzzles here.
• The Times keeps a running log of news related to grammar and language usage.