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10. Osama Bin Laden’s Death

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Date: May 1, 2011

Al Qaeda leader Osama bin Laden was killed in a firefight with U.S. forces in Pakistan in the spring of 2011, ending a nearly 10-year worldwide hunt for the mastermind of the Sept. 11 terrorist attacks.

It was the biggest national security victory for President Barack Obama since he took office in early 2009 and could give him a political boost as he seeks re-election in 2012.

Former President George W. Bush, who vowed to bring bin Laden to justice "dead or alive," but never did, called the operation a "momentous achievement" after Obama called him with the news.

Besides 9/11, Washington also has linked bin Laden to a string of attacks, including the 1998 bombings of American embassies in Kenya and Tanzania, and the 2000 bombing of the warship USS Cole in Yemen.

Photo: Tom Williams | Getty Images  || Source: CNBC.com, Twitter