Having written that, I realise it's not good enough. It's not just about habit; it's about feeling secure. If you think your neighbours are about to murder you, burn down your house, wreck your shop, rape your children - well, then of course that creates a situation of unbearable insecurity where it seems to make sense to get your retaliation in first.
Added 19 June 2015: And immediately I get one! The Institute of Economics and Peace has ranked 162 countries for the period 2008 - 2015 on a Global Peace Index, using 23 indices of peacefulness and peaceableness - things like homicide rates, civil unrest but also military expenditure. The UK gets to position 39 in the 162, a bit ahead of France (45) and well ahead of the USA (94 - Saudi Arabia is at 95) with Russia near the bottom at 152. Right at the bottom we have Syria and Iraq. Right at the top we have Iceland and several European countres in the top ten along with New Zeland, Canada, Japan and Australia. One country in the top ten is from the former Soviet bloc, the Czech Republic.