WASHINGTON, May 2: For many young Americans based in their nation's capital, the night of May 1, 2011, will be one to remember. Minutes after news outlets reported that Osama bin Laden had been killed in a firefight with US forces in Pakistan, jubilant Americans began gathering outside the White House.

They arrived in the hundreds, waving the stars and stripes, wearing red-white-and-blue. Some climbed trees and scrambled up lampposts to wave the American flag as high as possible. Others distributed cigars to perfect strangers and rejoiced by blaring noise-makers.

The assembly had all the elements of a victory party.

Video footage of the hundreds-strong crowd beamed across the world showed a triumphant mass, celebrating the news with fist-pumping chants of “U.S.A., U.S.A.!” But for those who lingered in the throng, the revellers' uncertainty about what to chant served as a reminder of the moral and motivational ambiguities of America's fight against terrorism.

Many of the youngsters gathered explained that they had been in middle school when the Pentagon and the Twin Towers in New York City were attacked on September 11, 2001. Osama's death was, in their opinion, the culmination of the long war that has defined their coming of age.

“This is amazing! It's the beginning of the end,” said one third-year student who attends George Washington University.

To celebrate their nation's success, he and his classmates sang their national anthem and patriotic songs such as “God Bless America,” and “America the Beautiful”.

But in the midst of the joy, there was also anger. A few people held up placards that read, “Never forget,” alluding to the 9/11 attacks. Others screamed Osama's name along with four-letter expletives.

One group of college students sang, “Osama, Osama, hey, hey, goodbye.” Another group started to boo Pakistan, though the crowd did not follow through with that rally.

One woman dressed up as a blue penguin ran through the crowds with a large banner that read, “Justice is Done!” “I've been waiting for this day for 10 years,” she shouted. “America is just and free! Think twice before attacking again,” she added.

A middle-aged couple who had been dining near the White House were more reserved. “It's great to see the youngsters so excited, but we're not done with this yet,” said the husband. “Other Osamas will come in his place; we need to think through carefully what this means.”

As a reminder that the killing of Osama is extremely significant in the context of domestic American politics, one of the most popular chants of the night was “Yes, we did!” A throwback to US President Barack Obama's 2008 presidential election campaign slogan, the chant highlighted the partisan undertones of a celebration that should have brought together a country that the president himself described as “indivisible” moments earlier in his address to the nation announcing Osama's killing.

In response, young Republicans chanted former president George W. Bush's name, and waved the Confederate flag.

But they acknowledged the importance of the event for Obama's presidency.

“This is huge for Obama,” said one young man draped in a southern states' flag. “It could get him re-elected for sure.”

Despite all the excitement on Pennsylvania Avenue, some Americans remained oblivious to the news at 1:00am on Monday morning. A few blocks away from the White House, a woman was shouting into her cellphone: “They've killed Osama… You know, Bin Laden. The big terrorist.” After a few seconds listening to the person at the other end of the line, she cried, “not Obama! Osama!”