The WoW general forums have been on a bit of a nostalgia kick lately. First, someone posted old maps of Azeroth from WC1 and 2 for discussion. Now, Aest of Twisting Nether asks, "If somehow, the Horde and Alliance broke out into all out war, who would be left standing?" He also mentions that the Burning Legion, the Illidari and the Scourge have all taken a holiday, so they can't interfere.
Of course, the first time this happened, the humans banded together and took down the orcs after losing Stormwind. But like Aest mentions, things are different now. The Horde has been on a consistent upswing since the Second War, and is strong and united under the leadership of Thrall, whereas the Alliance has lost High Elves and have a very divided high command. Sure, the Blood Elves and the Forsaken are in the Horde less for "Yay, Horde" and more for "Let's get revenge on our enemies", but that works okay, especially since the Forsaken are in the weapons of mass destruction business.
Territory-wise, the Horde essentially controls all of Kalimdor. The two Alliance capital cities (Darnassus and the Exodar) and their two biggest military bases (Feathermoon Stronghold and Theramore) are all on islands, and thus easily cut off from the rest of the continent. The Horde also has a nice foothold in Lordaeron and Quel'Thalas, and even though the Alliance holds the center of the Eastern Kingdoms, Stonard, Grom'Gol, and Kargath are all strong outposts.
On the other hand, humans are the most populous race in Azeroth, and while the Alliance has lots of little divisions, the Horde has one big one that could break them (Orcs/Trolls/Taurens vs. Forsaken/Blood Elves.) Plus, the Alliance has better technology and their cities are made of actual walls, as opposed to the Horde's "let's throw up some tents and call it a day." And, as several Allies pointed out, Alterac Valley has shown that the Horde will go to pieces as soon as they're asked to defend anything.
In the end, it would probably come down to the Steamwheedle Cartel. Goblins historically have more Horde sympathies, and if they joined up, it would be the end of the Alliance. If they didn't, the Horde would probably take all of mainland Kalimdor but lose their allies in Undercity and Quel'Thalas, making it a draw. I can't see the Alliance taking Kalimdor, especially since their air force is dependent on engineering devices that blow up half the time.
What do you think? Who would win in a fight today -- the Horde or the Alliance?