Is [water as a cause of war](http://www.nature.com/nature/journal/v458/n7236/full/458282a.html) overrated? Wendy Barnaby argues that, because it is possible to import ‘embedded water’ in the form of food, it’s usually better to trade food than to fight over water. I’m unconvinced (you could equally call industrial products ‘embedded oil’ and deny the likelihood of energy wars). Nice to have an anti-cassandra, though.