The night before Barack Obama’s inauguration in 2009, he quietly excused himself from dinner with his family at Blair House to receive a military briefing about the nuclear football — the briefcase containing nuclear launch codes that goes wherever the president does.

“One of the military aides responsible for carrying the football explained the protocols as calmly and methodically as someone might describe how to program a DVR,” Obama wrote in his recent memoir. “The subtext was obvious. I would soon be vested with the authority to blow up the world.”

But at that moment, the man about to make history as the nation’s first Black president was deeply worried someone would try to blow him up.

All inaugurations are, in the lingo of security experts, high-value targets for attack. In President-elect Joe Biden’s case, Washington has been transformed into a security fortress because of concern that the right-wing extremists who attacked the Capitol earlier this month will return to wreak havoc, or worse, on the inauguration.

For Obama, the country was still dealing with international terrorism threats in the wake of the Sept. 11, 2001, attacks and the ensuing wars in Iraq and Afghanistan. In the days before his swearing-in, President George W. Bush’s national security team warned Obama that there was credible intelligence about a planned attack on the inauguration by Somali terrorists.

Obama’s team, including incoming Secretary of State Hillary Clinton, scrambled into action, meeting in the White House Situation Room with Bush’s advisers, according to a New York Times account of the events. The image of the Capitol or the Mall being attacked while Obama was being sworn in would, even if he wasn’t hurt, be catastrophic for the country.

“Is the Secret Service going to whisk him off the podium so the American people see their incoming president disappear in the middle of the inaugural address?” Clinton asked, according to the Times. “I don’t think so.”

They needed a plan.

Rahm Emanuel, Obama’s sometimes-volatile incoming chief of staff, called David Axelrod, Obama’s chief strategist, on his cellphone.

“Can you call me back right away from a hard line?” Axelrod recalled Emanuel as saying this week for CNN, where he is now a political commentator.

“Rahm sounded a bit agitated, which wasn’t entirely unusual,” Axelrod continued. “But the fact that he was asking me to call from a landline rather than my cellphone was a tip-off that something was amiss.”

“I’m going to tell you something you can’t share with anyone,” Emanuel told Axelrod. “There is a serious threat on the inauguration.”

Emanuel was working on a contingency plan in case of an attack during the ceremony. Obama would need to instruct people how to evacuate and project calm. Emanuel wanted Obama to have a prepared statement to read, but the threat was a closely held secret. Obama had not even told his wife, Michelle.

“I can’t read the speechwriters into this, so I want you to write a brief statement for the President-elect,” Emanuel told Axelrod. “Meet him right before the ceremony in the Speaker’s office and give it to him. He’ll put it in his pocket in case it’s needed.”

So that’s what Axelrod did.

“I delivered the remarks to the President-elect, as planned,” Axelrod recalled. “He slipped them into his coat pocket without reading them, and we exchanged a few words about the journey on which we were embarking.”

Then Obama walked out to the stage, ready to the address the country.

“My fellow citizens,” he began. “I stand here today humbled by the task before us, grateful for the trust you’ve bestowed, mindful of the sacrifices borne by our ancestors.”

The threat, it turned out, had been a false alarm.

Obama kept speaking, uninterrupted.

“I felt satisfied that I’d spoken with honesty and conviction,” Obama wrote in his memoir. “I was also relieved that the note to be used in case of a terrorist incident had stayed in my breast pocket.”

Read more Retropolis: