Joshua Goldstein sees it as a real possibility:
The late peace researcher Randall Forsberg in 1997 foresaw "a world largely without war," one in which "the vanishing risk of great-power war has opened the door to a previously unimaginable future — a future in which war is no longer socially-sanctioned and is rare, brief, and small in scale." Clearly, we are not there yet. But over the decades — and indeed, even since Forsberg wrote those words — norms about wars, and especially about the protection of civilians caught up in them, have evolved rapidly, far more so than anyone would have guessed even half a century ago. Similarly rapid shifts in norms preceded the ends of slavery and colonialism, two other scourges that were once also considered permanent features of civilization. So don't be surprised if the end of war, too, becomes downright thinkable.