Defence planning is a long-term deal - it takes "decades to acquire weapons systems such as submarines." William Leben (letters SMH today) then makes the laudable point that "intelligent planning looks to tomorrow, not today." O.k, it takes a long time to plan for war. But the question is, how long does it take to plan for peace? 

Conventional thinking condemns us to the notion that defence planning is planning for peace; this has been the wisdom for centuries. The problem is that for centuries we had war - where the defence of one nation always is the aggression of another. We have to ask ourselves if conventional thinking is not the culprit that has repeatedly lead us to wars.

Recently our government has produced a white paper detailing 'defence' plans. It contained details about billions of dollars of weapons acquisitions. Not surprisingly our neighbours viewed it with suspicion.

If our thinking was changed, if we were to review the wisdom of spending obscene amounts of money on weapons systems, would we increase the long term prospects for peace?

It will indeed take decades, if not generations to bring about a meaningful change. But don't we owe this to future generations? I believe the long term survival of human kind depends on leaders now making the adjustments in their thinking - Barak Obama has taken the first step: "I don't just want to end the war, I want to change the thinking that got us into war in the first place." 

An important advance toward long lasting peace would be gradual disarmament, rather than planning for the opposite.