It's an interesting twist that the recent Sept. 11, 2011, anniversary marks two momentous events — 10 years since the multiple terrorist attacks in the United States that spawned a worldwide "war on terror", and six months since the devastating combination of earthquake, tsunami and nuclear plant disaster in Japan. These apparently disparate events share some important implications.
Where was the fourth airliner on Sept. 11, 2001, headed? It crashed in a Pennsylvania field as passengers and crew fought the hijackers, but what was its target? The White House or Capitol Hill is generally thought most likely, though some scholars have concluded that when it crashed, flight UA93 was heading for the Three Mile Island nuclear power plant.
A recent report "The U.S.-Russia Joint Threat Assessment on Nuclear Terrorism," from Harvard University and the Russian Academy of Sciences, notes that al-Qaida and North Caucasus terrorist groups have consistently stated that they seek nuclear weapons, and have attempted to acquire them. The other nonstate terrorist group known to have systematically sought to obtain nuclear weapons is the Aum Shinrikyo cult group responsible for the release of sarin nerve gas in the Tokyo subway in 1995.