Beneath Joe Biden’s Folksy Demeanor, a Short Fuse and an Obsession With Details

The commander in chief was taking his time, as usual.

It was late March, and President Biden was under increasing pressure to penalize President Vladimir V. Putin of Russia for election interference and the biggest cyberattack ever on American government and industry. “I have to do it relatively soon,” he said to Jake Sullivan, his national security adviser.

Mr. Biden had already spent the first two months of his presidency debating how to respond to Mr. Putin, and despite his acknowledgment in March that he needed to act quickly, his...