No matter what position you begin with, take eastern Australia with your first move. This will leave you with no resistance in Australia. From there, don't let anyone hold N. America and you will eventually win the game every time.

take australia, push through the indonesia and that and hold ur lines, try to only have 2-3 fronts, have atleast a group of 3 behind the fronts, prefferably covering 2 fronts. hold the line use ur cards to build up while push pulling the line, eventually the ai will kill each other and u can take the the 'winner/s'. if u cant try to stop the enemy bonus of holding a full continent while u maintain urs. hold the america side and push Europe, take africa and surround america on 3 sides, u should have plenty of cards from picking of other ai's, try to get player 1 or 2 XD gd luck...if ur below that its gonan be tough.

It's possible. Pay attention each turn to the turn order, how many cards each enemy has, and where the AI can attack from. Set them up to attack each other, and don't take fights where you'd end up dominated after the next turn sequence

id also take risks and try to take out players last territories so you get their cards and forces you to re draft and start your turn over with a lot more troops

I respectfully disagree.
Start/quit/restart, until you begin with 3 in Australia. Then just let your opponents beat each other up. While you build troops, take easy territories for cards, and try to keep your main force 1 tile away from another big force. Winning is nearly assured then.