JOHN Shaw says in his letter (Courier, November 7) that "no generation has ever managed to prevent war or involvement in conflict". That may be true but is that a situation we are happy to accept? How  much effort do we put into peace-building as compared to military expenditure?    The UK spends £46.4 billion on defence (the fourth largest military spender in the world) and the government provides subsidies to the arms' industry. For every £400 of our taxes spent on weapons, £1 is spent on peace building.   As a Quaker I wear a white poppy to show my commitment to seeking ways of promoting a more peaceful world.    I had relatives who died in the First World War and, like the Royal British Legion, I remember them with respect and sorrow. But I also remember many Quakers and others who sought to prevent the war taking place or refused to join up.   Many of them ended up in Dartmoor Prison, and some didn't survive the conditions they had to endure. If we seek to build a more peaceful and just world, we would do well to heed the words of Albert Einstein that "Peace cannot be kept by force, it can only be achieved by understanding." Gerald Conyngham Old Tiverton Road Crediton