George W. Bush's doctrine of endless war in Iraq and Afghanistan and the continued cannibalization of the U.S. economy. Squandered chances given by the end of the Cold War. A new USA, the National Security Fortress.

Invertebrates don't always operate alone. True society was the last feature to evolve in invertebrates, as recently as the time of Tyrannosaurus. In the last programme see the tensions below the surface in some of the great social structures built by insects, and witness the carnage when an ant colony and a termite colony wage war.

'Crude Awakening'- To combat the worst environmental disaster in American history, BP and the Coast Guard dumped nearly 2 million gallons of a chemical dispersant called Corexit into the Gulf. But instead of helping clean up the spill, Corexit made things worse. Shane Smith heads to Louisiana to report on the lasting effects of the BP oil spill. 'The Enemy of My Enemy' - Yemen, the fractured state in the Arabian peninsula, is at the top of the worry list for President Obama's national security team, and the rise of Al Qaeda there is only half the reason why. The real trouble is a current threat posed by the little-known Houthi rebel movement in the north of the country - a grassroots army, allegedly funded by Iran, that has never granted access to any other Western film crew before. Ben Anderson goes deep into Houthi-controlled territory to learn about the group that's fighting, and beating, Al Qaeda in the east, Saudi Arabia in the north, and Yemen's central government in the south.

Rock became a vehicle for artistic ideas and theatrical performance. From the pop-art multi-media experiments of Andy Warhol and the Velvet Underground to the sinister gentility of Peter Gabriel's Genesis. We follow Pink Floyd from the fated art school genius of Syd Barrett through the global success of Dark Side of the Moon. The film explores the retro-futurism of Roxy Music and the protean world of David Bowie.

In recent years, close study of the aging process has opened up new ways that could help us all live healthier for longer. Can we move beyond treating individual diseases, and instead treat the aging process itself? But would a longer life necessarily be a better life? A loose-knit group of researchers believe the real breakthrough is extending our health span - the period of life spent free of disease". Hear from Laura Deming, who dropped out of M.I.T. at the age of 14 and committed herself to finding and funding projects that can expand the human health span, and Dr. Brian Kennedy, whose work in the basic biology of aging has been crucial to the development of countless other researchers' work.

American exchange student Amanda Knox is convicted and eventually acquitted for the 2007 death of another student in Italy. Was she a cold-blooded psychopath who brutally murdered her roommate or a naive student abroad trapped in an endless nightmare? Directors Rod Blackhurst (Tribeca Audience Award-winner Here Alone) and Brian McGinn (IDA Award-winner Chef's Table) and producer Mette Heide (Peabody Award-winner India's Daughter) explore the notorious case that made headlines around the world.