Careful, there: some vindictiveness ("if you attack me in Africa despite our pact, I will go totally apeshit on you for the rest of the game") is an essential part of playing e.g. Risk well (in our group) - naive consequentialism ("looks like I lost Africa, taking Australia from (unrelated player) seems best now") does not work very well on intelligent and adversarial agents.

Totally agree. I'm ruthlessly vindictive but perfectly trustworthy (meaning I refrain from making promises I do not keep) when it comes to strategic situations like that. It looks superficially like being completely unsophisticated but it works.