What was the last war that caused no pollution?

22nd July 2009

Asked by: Tom Smith, Leeds

The idea of an environmentally-friendly war might strike some as a bit odd. There's no doubt that the use of chemical weapons like the herbicide Agent Orange during the Vietnam War caused decades of ecological problems after hostilities ended. For a war leaving no long-term pollution, it's necessary to go back at least to the early 15th century, before the widespread use of the heavy metal lead as ammunition.