Two years ago, a triumphant US President Barack Obama declared "justice has been done" after al-Qaida founder Osama bin Laden was killed by US special forces operating inside Pakistan. However, the ghost of terrorism and extremism continues to haunt many parts of the world, including the United States, raising concerns about the prospects for the world's anti-terror campaign.

Many in the world expected it would be the end of al-Qaida when bin Laden died. However, despite the fact that al-Qaida has been dealt a heavy blow, what has happened in the past two years indicates terrorist groups are taking advantage of the Internet and regional social unrest to reorganize.

The jihadist groups, which were squeezed out of Mali by Western intervention, have moved north, crossing the Sahara through Algeria and Niger to Libya, posing a threat to Libya's bleak security outlook.