the moral justifications for communism and moral arguments against capitalism and even vassalage to the US empire in particular can be considered in moral philosophy. that's not a perversion at all. Treating all political aims as interchangeable is the perversion-- and to the extent that they can evaluate ideology at all, an act utilitarian cannot treat aims as interchangeable since an act utilitarian is committed to weighing the particulars. it matters what you want. it matters whether something is true. it matters what you are trying to defend or attack. Considering these things is just inconvenient if your university is getting funding from a predatory ruling class of some kind; then, moral philosophy is about being a neutral arbiter on the battlefield between right and wrong. Maybe wrong is in the right, we don't know!
Right, but there's no suggestion to treat them interchangeably. An act utilitarian would look at
how each movement and political philosophy has impacted people and draw conclusions about what the response should be. Whereas a rule-- such as the one you drew up-- doesn't appeal to the impact or practices of the movement at all. There is no
consideration there; just blind adherence to a broad descriptive term.
And so sure, we'd end up with a rule that allows overthrowing Batista but not Castro. But it would also disallow the people getting rid of Pol Pot.
a rule approach isn't perfectionist, though. efforts to make progress toward justice, as a rule, can be good (or at least acceptable) even if they seem to reduce utility (in whatever way that is measured). as a rule, it is also a good idea to seriously consider the consequences of actions which entail risks-- it is not some kind of a contradiction for a rule to say that-- but the idea that morality turns on what happens as a consequence at the very least is not quite right. a peasant rebellion with just aims that ended up being crushed is not immoral for having been attempted.
That appears to be a question of incomplete information. The decision to revolt-- which is what we're judging-- comes before success or failure are known to the decider. Therefore we can judge likelihood and risk, but not take definite outcome as a given in our calculation.
Had the peasant leader known for certain that the revolt would fail, and that nobody's lives would be improved by it, then it would indeed be immoral to launch it.