A decade after the September 11 attacks, US President Barack Obama was able to declare on Sunday: "Justice has been done".

In a sudden and dramatic nationwide address to the US people that night, Obama announced Al-Qaida mastermind Osama bin Laden was killed by US forces operating deep inside Pakistan and was confirmed dead.

Given that bin Laden had become a synonym for global terror, his death could mark a milestone in the international efforts to fight terrorism and serve as a morale booster for the United States.