If we continue to expend our resources on protecting ourselves from each other then won't we waste them on not protecting each other from ourselves?
A vicious cycle like this is perpetuated by traps such as the Prisoner's Dilemma and No-Win Situations. Ideally, resources could be allocated in a way for everyone to come out a winner. However, given the current global political climate and lessons learned from history, humanity is a long way from not wasting resources. Let's just chalk it up to more lessons to be learned...