A history of power politics from the construction of the German battlefleet to Gorbachev's 'new thinking'. The unwillingness of all the Great Powers to recognise that war, in Ivan Bloch's 1899 phrase, had become 'impossible except at the price of suicide', resulted in two unprecedentedly great wars. These in turn gave impetus to a decline of power politics which gathered pace after 1945. Nuclear weapons imposed a straitjacket which Soviet revisionism was unable to break out of. Moral revulsion, technological advance and economic growth facilitated the emergence of a norm-based 'accomodatory' culture, which now offers a basis for a wider post-Cold War order.