President Barack Obama’s announcement Sunday night touched off a wave of public elation, as chants from a raucous crowd outside the White House alternated between “U.S.A.” and “Hey, hey, hey, goodbye.” Family members of bin Laden’s American victims wept with joy and relief. And the news produced something approaching national unity at a divided moment, as Republican presidential candidates put aside their criticism to praise the administration and the military for a daring strike inside Pakistan.

And yet the president’s late night statement, perhaps his purest moment of connection with the American people, left unresolved the lingering question of whether – after the emotional satisfaction, symbolic echo, and propaganda victory – the death of Al Qaeda’s hunted leader would bear heavily on U.S. national security.

“The death of bin Laden marks the most significant achievement to date in our nation’s effort to defeat Al Qaeda,” Obama said. “Yet his death does not mark the end of our effort. There’s no doubt that Al Qaeda will continue to pursue attacks against us. We must –- and we will — remain vigilant at home and abroad.”

For Obama, who has been sharply criticized for his lack of decisiveness in the early stages of the Libya operation, and dismissed as a military naif by conservatives — the decision to approve the raid on Abbottabad was an enormous risk. There was no guarantee bin Laden was actually in the compound, and no assurance that the Navy SEALs helicoptered into the compound wouldn’t share the fate of the eight service members who died in Jimmy Carter’s “Desert One” failed attempt to rescue American hostages in Iran three decades ago.

“I give the president full credit for this, it took a lot of guts,” said House Homeland Security Committee Chairman Peter King (R-N.Y.), whose district was home to dozens of New York City firefighters and cops killed in the attack on the World Trade Center on Sept 11th 2001. “He’s the commander-in-chief, he was the guy who put it on the line. There was no guarantee –none - that this would work. We could have had our helicopters shot down… It was a really delicate operation.”

Rep. Gary Ackerman, a Democrat who represents nearby Queens, was more pointed: “This was a ‘mission accomplished’ moment President Bush could have only dreamed of.”

That the final planning of an operation whose complexity and stiletto success rivals the 1976 Israeli hostage rescue in Entebbe, Uganda, took place during a week dominated by Obama’s birth certificate and his comic tongue-lashing of Donald Trump at Saturday’s White House Correspondents’ Association dinner makes the triumph all the sweeter for the president. While Obama was publicly decrying birther “silliness” – or mocking the triviality of Trump’s decision-making on “Celebrity Apprentice” he was privately ordering one of the riskiest military decisions made by a commander-in chief in recent years.

Two years ago, Obama tasked CIA Director Leon Panetta to prioritize the hunt for the 9/11 mastermind, a response to the perception that the Bush administration had allowed the hunt for bin Laden to back-burner. Senior administration officials say the trail heated up about a year ago when they discovered the identity of a key bin Laden courier – and linked the man to the construction of a fortified compound 35 miles north of Islamabad bristling with barbed-wire, 12-foot walls and packed with a mysterious family that burned its own trash.

After months of surveillance and analysis – and no fewer than nine Oval Office meetings on the topic – Obama authorized a daring helicopter assault on the mansion, culminating at around 7 p.m. Sunday night when the president was told that the “high value target” killed while resisting U.S. troops at the compound was, in fact, the man responsible for 3,000 deaths a decade ago.

The final decision to authorize the assault came at an 8:20 a.m. meeting Friday in the White House diplomatic reception room with chief of staff Bill Daley and national security adviser Tom Donilon. By 3 p.m., the formal orders were produced and Obama spent most of Sunday – apart from a nine-hole round of golf – monitoring the operation in the Situation Room.

By 3:50 p.m. Sunday came word that bin Laden was in the compound, followed by firm confirmation the remains in U.S. custody were his, officials said.

Still, confusion remained about the exact circumstances of the shooting: Senior intelligence officials say that Pakistani government officials were kept out of the loop to ensure the security of the mission, but CNN early Monday reported that members of the ISI, the country’s intelligence service, were at the mansion during the firefight.

In a conference call with reporters after Obama’s remarks Sunday night, senior administration officials said the risky, 40-minute operation in the Islamabad suburbs had been justified in part by its strategic consequences.

“The loss of bin Laden puts the group on a path of decline that will be difficult to reverse,” one senior administration official said, arguing that bin Laden’s successor, Ayman Al-Zawahiri, lacks both bin Laden’s popularity and his unifying stature.

And New America Foundation fellow Peter Bergen, a longtime watcher of bin Laden and his group, declared the killing “the end to the war on terror.”

“There’s no one that can replace him in Al Qaeda,” he said.

Bin Laden had already been shoved aside in the months before he died by an “Arab Spring” in which fantasies of caliphates and Islamic law seemed merely irrelevant to the young crowds risking their lives not for Islamic law but for democratic participation. And the U.S.’s frustrations in Afghanistan, ten years after bin Laden’s presence prompted an American invasion, don’t appear to be alleviated by his death – though it may produce a new wave of calls for a swift withdrawal.

Still, the national elation at least briefly jolted leaders of both parties out of their political trenches, and into ready agreement with remarks by Obama that repeatedly invoked the period after 9/11 in which “we were united as one American family.”

“This is a great victory for lovers of freedom and justice everywhere. Congratulations to our intelligence community, our military and the president. My thoughts are with the families of Osama bin Laden’s many thousands of victims, and the brave servicemen and women who have laid down their lives in pursuit of this murderous terrorist,” said former Massachusetts Governor Mitt Romney.

The elation may have been felt most intensely by the family members of bin Laden’s victims.

“I’m ecstatic. There are no words. I’m sitting here crying,” said Lee Ielpi, a former New York City firefighter who lost his firefighter son in the attacks.

“I’m not a big fan of Obama but he has continuously supported these precision strikes in the war on terror,” said Tim Brown, another former firefighter who is a leader of the conservative group 9/11 Families for a Safe & Strong America. “God bless President Bush and God bless President Obama for doing this. It’s huge closure for the families, as much as we could have. It’s huge for us.”

For Obama, it was the consummation of a belligerent promise: “We will kill bin Laden,” he said in an October 2008 debate with Sen. John McCain. During the campaign, he had raised eyebrows with a warning that if Pakistan wouldn’t authorize American efforts against bin Laden, an Obama administration would ignore their sovereignty, which appears to have been what happened Sunday.

Maggie Haberman and Byron Tau contributed to this story.