Here’s Why It Could Take Days for Flights to Return to Normal

With hundreds of planes out of position and crews out of hours, restarting the nation’s flight system is no easy task.Travelers at George Bush Intercontinental Airport in Houston on Saturday, the day after a nationwide ground stop snarled air travel.

N Niraj Chokshi

Ground Stop Highlights Chronic Vulnerabilities in Air Traffic System

The Federal Aviation Administration’s aging air traffic control infrastructure has had several disruptive failures in recent months, as officials have sought to make upgrades.Ronald Reagan Washington National Airport in Arlington, Va., after the F.A.A. grounded all flights nationwide on Friday.

K Karoun Demirjian

Nvidia Scandal Prompts Questions of What It Means to Be a Spy

U.S. intelligence agencies believe a woman who had an affair with Jensen Huang was a Chinese asset. But there is much more that they are still assessing about her role.There remains much that intelligence agencies are assessing about Alice Huang, whose relationship with Jensen Huang has come under i

J Julian E. Barnes, Maggie Haberman and Jonathan Swan

What’s Behind the Trump-Huang Relationship?

President Trump’s show of support for Jensen Huang as he was under fire was a remarkable moment in a relationship that barely existed two years ago. Our White House correspondent Maggie Haberman explains how Mr. Trump came to see Mr. Huang as a modern-day Henry Ford.Jonathan Ernst/Reuters

M Maggie Haberman, John Pappas, Gilad Thaler, Thomas Vollkommer, James Surdam, Edward Vega and Nikolay Nikolov

The Jensen Huang Scandal Has Shocked Even Scandal-Prone Silicon Valley

As Jensen Huang abruptly departs, the tech community grapples with an eternal question: Why do the smartest and most successful men so often act so stupidly?The revelation that Jensen Huang had a romantic relationship with Alice Huang changed the chatter in Silicon Valley from soaring I.P.O.s to taw

D David Streitfeld

How the University of North Carolina Tried to Avoid Trump’s Wrath

The University of North Carolina’s chancellor tried to protect the school from the Trump administration. Work on cancer, suicide, AIDS and coronaviruses was hit anyway.Students crossing the campus of the University of the University of North Carolina at Chapel Hill in September.

A Alan Blinder, Stephanie Saul, Irena Hwang, Benjamin Mueller and Mike Belleme

‘Get Focused on London’: How Iran’s Agents Attacked European Targets

A wave of assaults in Britain and elsewhere in the spring sowed fear across Europe. Prosecutors shed new light on how Iran took aim at U.S. allies.An arson attempt at a synagogue in London was part of a wave of attempted attacks on Jewish targets in the West that the authorities blamed on Iran and i

A Adam Goldman