If you haven't come to blows during a game of Risk you're playing it wrong.
Fuck that, it's just a game. I'm the most competitive person you'll ever meet, I hate losing. But it's still a game. Whenever me and my bro would play risk online with other people in teamspeak, we'd always still attack each other if it was in our best interests.
You make sketchy deals (i.e. we'll stack 10 units on the border) and then when it's beneficial, you back stab the person you made a deal with. No hard feelings afterwards, nobody cries for weeks or gets unfriended on Facebook. You try to do better next time.
Too many people these days (I blame the younger generation, i.e. 20'ish and under) take things too seriously. It's the same reason we still have the crpg team balance system allow pub stomps to happen. I don't mind going up against my clan mates, in fact if I see one on the battlefield I'm going to try and sneak a couched lance in their back when they are engaged with my teammates. It's just a damn game.