I'm an abjurer of optimism and pessimism equally, but hope can be useful. In a way the situation is even worse than your original comment suggested. More than just the indifference of being 'out of vogue', there's a lot of active hostility to the very notion of peacebuilding, as some responses suggested. But in the end, the main alternatives to active institution-and-culture-building are either to passively await a randomish fate, or pure militarism (whether defensive or aggressive). It's entirely predictable, given the growth in technology, that either of those alternatives does lead deterministically to catastrophe. Peacebuilding, frustratingly intractable though the problems may seem, is really all there is.