My goodness, I must have struck a nerve, because you're really twitching spasmodically right now. The definition of aggression is perfectly clear: it's when a country invades another for any reason other than self-defense. You can't get around it, no matter how much you spin it, Tom.

Now, you can argue that sometimes aggression is justifiable because your enemy is planning aggression of his own, and without a preemptive strike, you would be overwhelmed. Fine, I can see the logic to that, I might be tempted myself to shoot first and ask questions later. As they say, it's easier to apologize than ask permission. But now it is no longer a question of definition, or "principles" is it? Now it's a judgment call. It's your opinion, your subjective interpretation of your enemy's motives, your prediction of his future plans. And not everyone is going to agree with you. Especially history, if you're not the one that gets to write it. Remember those non-existent WMDs?

As for why the Russians committed aggression in Afghanistan? Well, they did it for the same reason we did in Vietnam: the puppet regime they had installed was being threatened by a domestic insurgency, and they felt it was essential to their long-term security. They, just like us, felt they had the moral right to do so, as well as the treaty obligations; and we were both wrong. And we both deserved to lose.

As for who should have lost or won? Well that's a judgment call too, and totally irrelevant. The Viet Minh won in Southeast Asia, the Taliban won in Afghanistan. Now you tell me which one has given the world the most trouble?