Escalating games - don't bother getting a card in the first round. You want the cards you turn in to be worth the most. If you are in a game with a lot of experienced people at escalating, don't be surprised if you don't get a card by the 3rd round. Someone will cave in eventually though.
One of the better tactics if you are in a bind where your armies are low is to ensure that you have at least 2 armies on each territory versus 1. This creates a "minefield" effect and you get to use both dice on defense versus just one, which is usually a surefire kill.
Don't pull all of your armies into larges piles at first. This will leave you with a lot of 1s that are easy to take by all of the other players looking to get easy cards - let them make that mistake. At least, that's what I consider it.
Keep a low profile and try and have at least a 3 spot in each continent. It will make you harder to take out because someone that is wanting to take you out will not want to stretch themselves out to get you.
While I am still working on my "every game is winnable" theory, these are just rule of thumb thoughts I have as I only play escalating games. I'd post some of my other ideas, but I'm still trying to perfect them.
Enjoy..