Who won the (First World) War?

I once read a review of James McPherson's history of the American Civil War, Battle Cry of Freedom. It argued that after a century and a half, McPherson had finally provided a one-volume history of the Civil War that was comprehensive, authoritative, dispassionate, and above parti-pris side-taking. On the strength of the review, I bought and read Battle Cry of Freedom, and while Civil War history writing has hardly come to a full stop (!), it does make a pretty impressive survey and useful reference.

Maybe the world need a little more time to get to the same place with regard to the First World War.  I'm often impressed with Canadian accounts of the war that stress the vital contribution of the Canadian army to the Allied victory, when I'm aware that, say, British histories seem able to cover the same territory with only the barest mentions of a Canadian presence.

Seems the Americans have the same "it's about us, why don't they admit it?" attitude, judging by a recent essay in Time magazine by historian Geoffrey Wawro, author of Sons of Freedom: the Forgotten American Soldiers Who Defeated Germany in World War 1.  Wawro takes the position that France and Britain were on the verge of collapse and surrender when the Yanks arrived took charge, and swiftly put an end to the war.

Has there yet been a one-volume history of the First World War that is not a (British/American/French/German/Canadian...) account but an above-the-fray history, balanced and authoritative and reliable about all sides?  Nominations gratefully received.

Update, October 25:  Five Books, the pretty terrific site where experts are invited to nominate the five best books on practically anything (except, ahem, the history of Canada) proposes Michael Joseph's The First World War as "a balanced, modern interpretation"  and "incredibly rich and wise and balanced in the views that it takes." It's only 150 pages, which seems impossible