Twenty years on from the collapse of the Soviet Union the toxic legacy of its industries still lives on. For Assignment Angus Crawford travels to a remote valley in Georgia where research has shown that there are dangerous levels of arsenic in the soil and water and yet the local community remains unaware of the health risks.

Across the world the cost of basic commodities is soaring. Endless demand from China is blamed for the record price of copper; flood, fire and drought for boosting the cost of food; and political tension in the Middle East for the sharply-rising price of oil. But are such fundamental forces the whole story? Michael Robinson asks whether investors and speculators are making prices more volatile and examines the role of the giant traders, banks and companies which now increasingly dominate the world's commodity markets.

For months Yemen has been the scene of widespread unrest and anti-government protests. President Ali Abdullah Saleh has warned that if he stands down the country risks falling into the hands of extremists groups like al-Qaeda in the Arabian Peninsula. For Assignment, Natalia Antelava reports from the capital Sana'a, on how warnings like these feed into the very fear that shapes US counter-terrorism policy in Yemen.

In the space of just over ten days in March 2011, the United Nations Security Council passed two of its most significant, emphatic and far-reaching resolutions in decades. Claire Bolderson looks at how the world body used a new-found strength to intervene militarily in Libya and Ivory Coast and assesses how the decisions have changed the course of these two brutal conflicts.

The killing of Osama bin Laden has stirred deep suspicions about whether the Pakistani authorities knew the world's most wanted man was living quietly in Abbotabad. For Assignment, Owen Bennett-Jones explores allegations of a web of links between Pakistan's security forces and militant jihadists.

In the space of just over ten days in March 2011, the United Nations Security Council passed two of its most significant, emphatic and far-reaching resolutions in decades.

Jonathan Glancey looks at whether Dubai has a sustainable policy towards building in one of the harshest environments on earth. How does the city compare to neighbouring Doha?

On a moonless night on Sunday May 1st, four American military helicopters descended on a compound in the quiet town of Abbottabad in north-west Pakistan. Their mission to capture and if need be, kill, United States Enemy Number One - Osama Bin Laden. They succeeded and America's most exasperating manhunt was over. But how did the risky operation unfold both in Washington and in Pakistan? Rob Walker reports for Assignment.

On the 25th anniversary of the nuclear disaster at the Chernobyl power plant, presenter Olga Betko travels to Chernobyl - in her native Ukraine - to find the people who are living in what is known as the "dead zone".

Jonathan Glancey looks at whether Dubai has a sustainable policy towards building in one of the harshest environments on earth.