The United States had obtained “extraordinary detail” about the Kremlin’s secret plans for a war it continued to deny it intended, Director of National Intelligence Avril Haines later explained. They included not only the positioning of troops and weaponry and operational strategy, but also fine points such as Putin’s “unusual and sharp increases in funding for military contingency operations and for building up reserve forces even as other pressing needs, such as pandemic response, were under-resourced,” she said. This was no mere exercise in intimidation, unlike a large-scale Russian deployment in April, when Putin’s forces had menaced Ukraine’s borders but never attacked.

Some in the White House found it hard to wrap their minds around the scale of the Russian leader’s ambitions.

“It did not seem like the kind of thing that a rational country would undertake,” one participant in the meeting later said of the planned occupation of most of a country of 232,000 square miles and nearly 45 million people. Parts of Ukraine were deeply anti-Russian, raising the specter of an insurgency even if Putin toppled the government in Kyiv. And yet the intelligence showed that more and more troops were arriving and settling in for a full campaign. Munitions, food and crucial supplies were being deposited at Russian encampments.

Biden pressed his advisers. Did they really think that this time Putin was likely to strike?

Yes, they affirmed. This is real. Although the administration would publicly insist over the next several months that it did not believe Putin had made a final decision, the only thing his team couldn’t tell the president that autumn day was exactly when the Russian president would pull the trigger.