This books provides an in-depth analysis of the international legal aspects of the use of depleted uranium (DU) ammunition and armour. The military use of DU has been surrounded by considerable controversy, mainly as regards the health and environmental risks that such use entails. The debate about DU has thus far been highly polarised, with one end of the spectrum rejecting any risk whatsoever and the other end suggesting that the use of DU leads to severe health and environmental consequences, including Gulf-War syndrome, whenever it is used. Rather than settling these controversies, the book takes as a starting point a precautionary approach in light of the considerable remaining scientific uncertainties. It examines various principles and rules of international law, which would be at play if the health and environmental concerns regarding the use of DU were to materialise.