CarterJon, build enough naval landing points (is that what they are called) to allow you to invade with at least 3 corps. Some people also build airborne units and air transport points. The key is to capture the open port in the Peloponnese (a few hexes SW of Athens). This will allow your units to be in supply. Meanwhile also attack from Albania. the Greeks will be hard pressed to defend on all fronts. But as Sveint says it is not a cakewalk, especially if the British show up in force. You will probably need German help. But the reward is well worth it. Capturing Greece before March 41 means that Yugoslavia will join the Axis. So invading Greece is the right move; but it is not as easy as I mistakenly previously posted that I thought it would be. FYI, if you see me post one thing and Flavius post an opposing view, the smart money is on Flavius.
Sveint, imho, it is unhistorical. Not because historically Italy did not invade the Peloponnese; I mean the whole point of a game like this is to use strategies different from the ones that were used historically. No it is unhistorical because Italy did not have the logistical ability to have invaded Greece in 1940. The logistics of the D-Day landings required the greatest armada the world has ever seen and only 6 divisions were landed on the first day. Admittedly, each turn in Warplan is 2 weeks, but still it was beyond Italy's ability to do something like this. Having said that, I have no problem with them being able to do this in this game; after all it is only a game and a fun one at that.