When top officials from dozens of nations and international organizations convene in Tokyo on Monday for two days of discussions on the rebuilding of Afghanistan, they may not be aware that their efforts could spark unintended environmental and political side effects, according to experts.

"I am concerned that very few people have looked in depth at the Aral Sea issue, but many people are crazy about giving aid to Afghanistan," which lies upstream of the lake, said Mikiyasu Nakayama, a professor of agriculture at the Tokyo University of Agriculture and Technology.

Squeezed between the borders of Uzbekistan and Kazakstan, the Aral Sea was once the fourth largest inland body of water in the world. No longer. Since the 1970s it has been disappearing.