By the time he is sworn in Friday, Donald Trump will have undergone a haunting rite of passage: the classified briefing given to every incoming president that explains how he can order a nuclear attack.

While neither U.S. nor Trump officials would confirm the exact time or location of Trump’s briefing, several past presidents have been briefed on the nuclear codes at the historic Blair House, on Pennsylvania Avenue near the White House, hours before their inauguration.


“It's a sobering moment. It defines the ultimate obligation that you might have,” said Andrew Card, who served as chief of staff to George W. Bush and was with Bush just before and after his first nuclear briefing in January 2001.

It is also likely sobering for millions of the Americans who heard a series of Trump rivals warn last year that the New York mogul must never gain access to America’s massive nuclear arsenal.

"How can you trust him with the nuclear codes?" President Barack Obama said at one October rally. "You can't do it."

But America will do it on Friday. From the moment Trump is inaugurated, he will be trailed everywhere he goes by a military aide carrying a 45-pound black satchel colloquially known as the nuclear “football.” Inside will be the codes, war plans and communication tools needed to start a nuclear war.

By then, national security officials will have instructed Trump on the chilling steps he would have to take to order a nuclear launch that could, in theory, kill hundreds of millions of people.

Little is known about the briefing itself, which an Obama White House spokesman declined to discuss. Trump spokesman Sean Spicer would say only that “every step needed to assure a peaceful transfer of power from one president to the next is taking place.”

But nuclear experts and former presidential aides offered some detail and historical context for what they call a harrowing glimpse at a nightmare scenario.

Confronting the reality of nuclear war has left past presidents deeply moved, even shaken. In his 1999 memoir, Bill Clinton’s former spokesman George Stephanopoulos described seeing Clinton emerge from his nuclear briefing, held at 7 a.m. on the day of his inauguration.

“The man who would soon command the most powerful military force in the world emerged … silent and more somber than I’d ever seen him,” Stephanopoulos wrote.

Clinton wasn’t the only one moved. Stephanopoulos recalled that George H.W. Bush’s outgoing national security adviser, retired Gen. Brent Scowcroft, “slipped out of Blair House and into the street with tears reddening the rims of his eyes.”

Trump himself has spoken about the horror of nuclear weapons. “I’d be the last one to use the nuclear weapons, because that’s sort of like the end of the ballgame,” he said at a March 2016 MSNBC town hall.

But at the same event, Trump refused to rule out the use of nuclear arms, and cited the Islamic State as a possible target if “somebody hits us.”

Sources familiar with the shadowy world of the U.S. nuclear establishment said that Trump would customarily be briefed by the outgoing national security adviser, Susan Rice, along with the White House military aide responsible for the so-called nuclear football. Trump would likely be joined by his incoming national security adviser, retired Lt. Gen. Michael Flynn.

If the recent past is a guide, Trump’s briefing will occur Friday morning at Blair House, where Trump plans to spend Thursday night. Like Clinton, Obama in 2009 took his nuclear briefing on the morning of his inauguration, just before heading to an 8:30 a.m. church service.

The briefing itself does not involve grand nuclear strategy, nuclear experts and current and former U.S officials said. Presidents attend separate sessions in which military officials outline scenarios from all-out attack on Russia to war with China to limited strikes against rogue nations like North Korea.

Instead, Trump’s Friday briefing is meant to ensure that he understands how to quickly order a nuclear attack in the event of an emergency.

“The briefer is very, very military. It’s a military briefing,” Card said. “It’s not a briefing of the conscience. It’s by-the-book; it’s rote.”

“It’s kind of like how to use your remote control for the TV,” Card added.

The session guides a president in the use of the famous nuclear codes — which are not transmitted to missile silos, bombers and submarines but used, like a password, to verify the president’s identity when he sends a launch order to the Pentagon.

Timothy McBride, a former military aide in George H.W. Bush’s White House, said Scowcroft informed Clinton in their January 1993 meeting that he would be pulled aside in the U.S. Capitol building just after his swearing-in and presented with the nuclear codes.

Trump critics note with alarm that an American president does not need the approval of Congress, his Cabinet or any other entity to order the use of nuclear weapons. Experts say the secretary of defense could pre-emptively instruct the Pentagon battle staff officers responsible for transmitting such an order to disregard it, but whether they would is unknowable.

A president’s largely unchecked power to order a nuclear attack was the subject of campaign ads in support of Hillary Clinton last fall. In one, Bruce Blair, a former nuclear missile launch officer turned disarmament advocate, declared: “The thought of Donald Trump with nuclear weapons scares me to death. It should scare everyone.”

Since the end of the Cold War, the prospect of a president being forced to respond within minutes to a massive Russian attack — the main reason for a system that allows a president to order an attack quickly and unilaterally — has been greatly reduced.

But the Cold War system endures, in part because Russia maintains about 1,800 active nuclear warheads capable of hitting the U.S. (The U.S. keeps active about 1,400 warheads.)

And in recent months, many experts have warned that the prospect of a nuclear conflict with an increasingly belligerent Russia has grown — although Trump says he wants warmer relations with Russia and said in an interview over the weekend that “nuclear weapons should be way down and reduced very substantially.”

It is unclear whether such talk will assuage critics who warned during the campaign that Trump could not be trusted with the presidency’s most awesome power.

An October letter signed by 36 former nuclear launch officers, including Blair, warned that the pressures of nuclear command on a president “are staggering and require enormous composure, judgment, restraint and diplomatic skill.”

"Donald Trump does not have these leadership qualities. On the contrary, he has shown himself time and again to be easily baited and quick to lash out, dismissive of expert consultation and ill-informed of even basic military and international affairs — including, most especially, nuclear weapons,” the letter said.

But some believe that first-hand experience with the theoretical means of destroying much of the world could have a profound effect on Trump.

“You cannot take over such an authority without getting a sense of unbelievable responsibility,” said Hans Kristensen, director of the Nuclear Information Project at the Federation of American Scientists. “Not just to the nation, but to the planet.”