Because of the easily bottlenecked Ionian Sea. Italy can, relatively easily early on, stymie a Turkish advance through the Med. And a Turkey which builds armies to go north is going to freak out any sentient Austria.

I like Russia and France. Crush everything in between (which is everyone).

Ah, but doesn't (or shouldn't) the same problem arise with MAO? Of course, it cannot be held from the south, but progress from there can be made impossible. An Italian which cooperates in France's partition can usually be assured Marseilles (to gain entry to France), and while England and Germany are busy skirmishing with France's northerly-deployed fleets and scattered armies, Italy can get a foothold on Iberia. All of that is easily held from the south, and then England is stuck.

I changed it to "should be" because theory and practice obviously don't match up. The issue is the France-Italy dynamic. Italy players are told to focus east so much, and it messes up the whole opposite equivalent dynamic. MAO is every bit as much a bottleneck as Ionian, in strict geographic terms. But if Italy deploys east so much, that bottleneck is left open while the Ionian one is not.

So now my question is... why is Italy so often encouraged to go east?

Italy is encouraged to go east because of Turkey and Austria, IMO.

Turkey has only two ways of developing - north or west. It usually has hard time to go for Russia, unless Black Sea is open, and same applies to Russia. This means Turkey will attack Austria with Russia early on, creating a juggernaut. If Italy will head west, for France, it will leave its rear open while Turkey deploys its navies over the whole Mediterranean, while Russia rolls over Austria with its armies.

In addition, going west makes Italy to spread its units thin, which is problematic because of the low amount of builds Italy tends to get early in the game. In addition, if it manages to rip France with the aid of England and Germany, England will benefit more from it and head for the Mediterranean from the north, crushing Italy in between Turkey and England.

In addition, the dying Austria may want to nab some Italian SCs to save its ass.

Italy goes east against the Juggernaut, sure. But Juggernauts are not always on the cards. And when they aren't -- when Austria is allied against one or the other -- it behooves Italy to go west and get his gains there, I would argue. He can't get a piece of the Russian pie, and his share of Turkey will be marginal, maybe confined to Smyrna.

Meanwhile, presume he goes west. He can almost certainly get the assistance of England or Germany, whichever got left out of the Western Triangle. And if France is the odd man out, you will see England stymied by the French fleets built to combat him, and Germany will have a little difficulty in cracking the wall. If Italy comes in and breaks through from the south, the French position will usually be so scattered north that he can grab Iberia and Marseilles -- all easily held from the south. He can then turn his builds toward Austria.

italy can definitely get a piece of russia - with the rocky lepanto opening, (that is venice to tyrolia, rome to apulia) convincing Germany to let you take munich may be difficult, but convincing france to support you in shouldn't be.

From there one italian army can attack France, Germany or Russia. Depending on where the diplomacy take it (or even Austria forgoeing the orthodox automatic alliance between italy and austria)

ok it's only one unit into russia (the case for moving against france may be stronger) but italy can demand a center from it's austrian ally, or require greece (say) if Austria is not forthcoming a stab from the north with russian assistance will likely cripple austria anyway...

I just see this opening as having huge potential for Italy. (of course it partly requries convincing germany that giving up munich is a good idea, and as it happens germany can virtually guarentee he forces munich in 1902 (as you didn't move rome north to venice) The extra build can be used to put an extra fleet into the med - disbanding the army upon dislodgment if you want.

The juggernaut's success assumes england and germany don't work together in the north. (kicking russia back to stp) even with a northern opening from russia, england-germany can easily guarentee two builds each (Den + Swe for germany and Nor + Stp for england) a weak russian and non-aggressive italy can be enough for austria to hold off the juggernaut all on his own (well with english and germany help...)

so the call to go west beckons, and with an E-G alliance Italy can guarentee a swift french fall.

ok, i've clearly had too many loses as russia and too many sucesses as italy - but i still advocate winter-green if you can pul it off. see: http://en.wikibooks.org/wiki/Diplomacy/Alliances