A situation in one of my current games has led me to wonder what exactly the "spirit" of the game is. Here's the situation:

Playing as Italy, I allied with Russia against Austria and then Turkey. Meanwhile England, France and Germany fought amongst themselves, no-one really dominating. England was engaged in low-scale fighting Russia in Scandinavia.
With Turkey out of the picture, Russia turned on me. I couldn't have survived on my own, but an alliance England-France-Italy formed to take on the now very large Russia, and Germany. France sent three fleets into the Med to replace those I'd had to disband, and with French help, and Russia missing a turn or two, we fairly quickly eliminated Russia and Germany. In doing so, I grew very large, England slightly smaller, and whereas French gains had largely been limited to Germany, England occupied Scandinavia, StP, Moscow and StP. wherea I held most of Turkey, all of the Balkans, Austria and Italy.
England and I then turned on France.

Here's my question, what do YOU think the spirit of the game is?
Is it in keeping with the spirit of the game to attack an ally whose help ensured not only your survival but your prosperity, or do you "owe" him something?
Would agreeing to a 3-way draw be against the spirit of the game which dictates you should try to win (or at least reduce the number of players involved in a draw) whenever feasible?
And finally, is a win where you betray only one ally "better" (in any way) that a (quicker) win where you betray two?

I'm pretty certain that betrayal is the way to go if you're as certain to win as (I think) I am. This is obviously a game, and so the fact that this clashes with ordinary morality doesn't matter (I don't think), but does anyone think that we should apply ordinary morality in such situations? Morality such as repaying your debts, being trustworthy and loyal?

I'm looking forwards to hearing your thoughts.