Thursday, Jan 2, 2020 | View in browser

Good morning and happy New Year!

We’re covering mounting tension after the attack on the U.S. Embassy in Baghdad, devastating fires on Australia’s east coast and spectacular caves in Vietnam.

By Melina Delkic

Protesters outside the U.S. Embassy in Baghdad on Wednesday. Ahmad Al-Rubaye/Agence France-Presse — Getty Images

U.S.-Iran tension builds after embassy protests

Pro-Iranian protesters swarmed outside the U.S. Embassy in Baghdad for a second day, but dispersed after a few hours, when the militia leaders who had organized them called on the crowd to leave.

Unlike on Tuesday, when thousands marched around the embassy in response to deadly American airstrikes over the weekend and some forced their way through the outer wall, the protesters did not get into the compound.

President Trump tweeted that Iran was responsible, writing: “They will pay a very BIG PRICE! This is not a Warning, it is a Threat.” Ayatollah Ali Khamenei, Iran’s supreme leader, responded with a taunt, saying Mr. Trump “can’t do anything.”

Analysis: While the aftermath of the attack seemed to be under control, it played to Mr. Trump’s longtime worry that American diplomats and troops in the Middle East are easy targets, and it highlighted the vulnerability his administration faces amid impeachment and an election year.

A kangaroo rushing past flames in Lake Conjola, New South Wales, on Tuesday. Matthew Abbott for The New York Times

Australia sends in aid as fires devastate coast

Fire danger remained high as the country deployed military ships and aircraft to deliver supplies to towns cut off by growing wildfires. The death toll rose to at least 17 people, and several people are still missing.

Thousands in the coastal town of Mallacoota fled to the shore as fires ravaged their town and turned the sky red. People slept in cars, and gas stations and other businesses turned into makeshift evacuation shelters.

The fires are so fierce that they have created their own weather systems: A phenomenon called a fire tornado — turbulence caused by extreme rising heat — caused a 10-ton fire truck to roll over in New South Wales, killing a volunteer firefighter.

Context: Australia’s east coast is tinder-dry after three years of drought, and climate change has had a particularly visible impact on the country in its warmest decade on record. Still, the country’s prime minister has refused to talk about global warming.

Kim Jong-un, North Korea's leader, at a Workers' Party meeting in Pyongyang. KCNA., via Associated Press

What North Korea’s nuclear threats mean

Kim Jong-un declared on Wednesday that North Korea’s self-imposed moratorium on nuclear weapons testing had ended and vowed to expand the country’s arsenal, but he also showed a deep caution in confronting President Trump.

He moderated his threats — vague promises to show off a “new strategic weapon” in the near future and “shift to a shocking actual action” — by leaving out the specifics. Mr. Kim said his plans to expand North Korea’s nuclear capabilities could be adjusted “depending on the U.S. future attitude.”

Analysts say the North Korean leader is making a calculation based on political uncertainty in the U.S., where his counterpart faces an impeachment trial and an election. But it’s unclear how far he will go in his hard-line tactics.

Quotable: “I think we’ll see Kim continue to find ways to provoke Washington as a way to gain the upper hand in future nuclear negotiations without directly challenging President Trump,” one North Korea expert said.

Context: North Korea has not conducted a long-range missile test or a nuclear test in more than two years. Mr. Kim announced the moratorium in hopes that negotiations with the U.S. would lead the country to lift crippling sanctions. But the pledge was never understood the same way by both sides.

If you have some time, this is worth it

Millennial anxiety, 20 years on

Michael Okoniewski for The New York Times

For millennials, Y2K felt like an apocalypse. People wondered whether clocks would know which year to turn to, whether bank accounts would still work and whether planes would fall from the sky. Above, the remains of a survivalist store in Allegany, N.Y, in 2000.

Two decades later, our Styles desk looked at the legacy of Y2K panic — and how it left behind a bunch of nervous 30-year-olds.

Here’s what else is happening

Hong Kong: About 400 people were arrested after a police-approved demonstration turned violent on New Year’s Day. The police quickly revoked their permission, citing the violence.

Israel: Prime Minister Benjamin Netanyahu is seeking immunity from Parliament in a few corruption cases. He is likely to face accusations of putting himself above the law as he approaches an election.

Mexico prison fight: Sixteen inmates died and five were wounded at the Cieneguillas men’s penitentiary in the state of Zacatecas, after one of the worst outbreaks of violence in the country’s troubled penal system in years.

The Vatican: Pope Francis apologized for slapping away the hand of a woman who grabbed him in a receiving line, saying he lost his patience and set a “bad example.”

German zoo fire: Dozens of animals were killed when a fire that started shortly after midnight on New Year’s Day burned down a monkey enclosure at Krefeld Zoo in North Rhine-Westphalia.

Justin Mott for The New York Times

Snapshot: Above, the spectacular caves of Phong Nha, Vietnam. A couple turned an impoverished farming and fishing community into one of Vietnam’s premier adventure destinations — with most of the spending going directly to locals.

From Opinion: Now that our outsize expectations for tech have been leveled, “what’s coming in the next few years might be a lot better than you expect,” writes our columnist.

What we’re reading: The Washington Post’s list of what’s out and what’s in for 2020. “Since 1978, my former employer has compiled an annual scorecard of the cultural zeitgeist,” writes Chris Stanford, on the briefings team. “It includes helpful links for the terminally unhip, like me, who can’t make sense of most of the entries.”

Now, a break from the news

Ryan Liebe for The New York Times. Food Stylist: Simon Andrews.

Cook: This recipe for ground beef and macaroni is the most luxurious Hamburger Helper you’ve ever had.

Watch: Greta Gerwig onstage, Jack London on film and Broadway revivals are among 12 things that our critics are looking forward to this year.

Go: In his latest dispatch, our 52 Places columnist visited the final stops on his list: Tahiti and its island neighbors in French Polynesia, and wintry Calgary, Canada.

Smarter Living: One of the best things you can do for your health is to cut back on foods with added sugar. Our 7-Day Sugar Challenge shows the way.

And now for the Back Story on …

When to start (and end) a decade

Over the last few weeks, The Times has published many an article marking the end of the decade. However, several readers have written us arguing passionately that the decade still has another year to go.

In the sixth century, a Christian scholar named Dionysius Exiguus invented the anno Domini numbering system, in which 1 A.D. was supposed to indicate the year of Jesus’ birth. There was no year zero, so the beginning of the first decade of the Common Era started with 1 and ended with 10.

People ring in the new year in Ahmedabad, India. Sam Panthaky/Agence France-Presse — Getty Images

Like language, time is socially constructed. People celebrated the end of the century in 2000 because the dramatic change in numerals served as a convenient marker, and also because humans are drawn to round numbers. But the first year in the third millennium is — technically — 2001. That being said, someone born in 2000 was not alive in the ’90s.

Let’s have it both ways. Welcome to the final year of the 202nd decade, and also the start of the 2020s.

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

— Melina

Thank you
To Mark Josephson and Eleanor Stanford for the break from the news. Will Dudding, an assistant in the standards department, wrote today’s Back Story. You can reach the team at briefing@nytimes.com.

P.S.
• We’re listening to “The Daily.” Our latest episode revisits Ella Maners, a 9-year-old who was the subject of our special kids’ episode about facing fears.
• Here’s our Mini Crossword, and a clue: Drink sipped by Kermit in a popular meme (three letters). You can find all our puzzles here.
• A weekly column about the technology that Times journalists use found that, unsurprisingly, the smartphone was their most vital work tool.