Meta-game alliance strategy

These recent game show discussions have shown up at the same time that I friend and I got into a renewed debate about alliance strategy in war games. If you play games like Diplomacy, Risk, Samurai Swords (formally Shogun), or any war game that allows for alliances that may be made or broken, what type of ally are you?

Some additional descriptions:

1) Mutally Assured Destruction ally: you are loyal to the end, and expect the same from your ally. You announce, and then follow through with, a threat to destroy your ally if they attack you first. You will stop at nothing to make good on this threat, even if it means you both lose. Your alliances last the whole game, or end in bloody affairs. You have won in both situations...

2) Strong ally: You won't stab, and don't expect to be stabbed. If you are betrated, you are sad, and consider the new game situation. If you can see another way to win, you won't blindly attack your former ally. Otherwise, may as well pay him a lesson.

3) Weak ally: your alliances are fragile at best. Both parties understand this. You don't leave an open backdoor to your ally unless you have to. You expect to be stabbed, and look for good opportunities to stab your ally one turn before he stabs you. Your friends don't trust you, you don't trust them, but you still play together. You all know how to cheat at cards.

4) Dark ally: you make your ally think the alliance is strong, but you are going to get him. You pick your mark every game, befriend him, and make him your target. Machiavelli would be proud.

5) Either because you don't trust anyone, or don't want to be in the situation where you have to betray someone's trust, you don't like making alliances in these games. Let the others mess with politics, you like rolling the dice.

I answered "weak ally" in the poll. More specifically, #3 in the text sums up my position. I remember many college Diplomacy games with my roommate, his girlfriend, and our friends. Nobody ever wanted to be the 3rd ally in my roommate's alliance, because he and the GF adhered to the MAD (#1 in the text) strategy. Either you were going to be stabbed by them both at some point to further their power, or they were going to implode on each other and leave you alone to face the world.

When I used to play diplomacy, my friends and I got into the uneasy equilibrium in #3. But a friend I've recently started playing games with is more of a MAD ally: I've tried to convince him that breaking alliances is just part of the game, but he like to take them seriously.

I think this can only be considered in an iterated-trials environment. In a one-off, you treat the alliance in the most expedient manner--you honor it until it suits you to betray it. This could occur in a variety of situations, so I would call the one-time strategy the "pull the plug at any time" strategy.

If you are playing the game multiple times with the same opponent(s), things get much more complicated. If you adopt anything other than the "strong" strategy, potential allies won't be inclined to make alliances with you, and you could wind up being isolated. The MAD ally option might be good for teaching potential backstabbers just what the consequences would be.