If you total up casualties from the ongoing conflicts in Syria, Yemen, Libya, Iraq, Afghanistan, and Somalia then you might be surprised at just how many violent deaths have transpired in the past decade. What's more, many of these conflicts have significantly outlived WWII in duration. Will the humpty dumpty of Syria ever be put together again? Probably not as long as it's the proxy battleground for regional powers.
What we might be seeing, rather than real peace, is a disparity of safety from violence. Some countries will be bomb-wrecked hellscapes for decades, while others fund those conflicts but don't think about them too much (except for when terrorists show up to burst our bubbles).