This is actually a really interesting question. I suspect Peter nailed it with his excellent post, but I'd like to add a few thoughts, since it looks like the thread more or less died without addressing the additional questions you asked. My answers might not be the best, but maybe someone else could step in and refine this (or fix it), plus provide some sutta references or something.
Drolma wrote:Now I know things like natural disasters aren't the result of kamma. But for example, would the reign of George Dubya be a result of collective kamma? I have always found this confusing. Or was WWII potentially a result of collective kamma? Though many people had volition and performed action, Hitler is generally the only one blamed for things. But it wasn't the result of one person's incredible evil, right?
My understanding is that the web of conditions for even a single individual is so complex that you can't really know (unless you are the Buddha) exactly why a person is having a particular life experience. Since this is the case with a single individual, then imagine how much more complex it must be to analyze entire societies.
More concretely, though, I think common sense would demand that others besides Hitler share responsibility for the atrocities of WWII, and I think that if you look at the recent history of modern Germany, you'll find a great deal of soul-searching and even societal blame-accepting that was largely absent during the first difficult decades right after that war. The denial mostly passed, and this generation is coming to terms with the widespread complicity that enabled Hitler.
So, sure, in any analysis I think we have to acknowledge that the prevailing political order in any nation will be the result of a complex blend of conditions including the volitional character of its present leadership, but also including the manner in which its people react to that, the economic realities, tradition, etc.
One question is, how would the concept of collective kamma inform one's path of practice?
Drolma wrote:So if I pay taxes right now and that tax money goes to supporting wars, am I participating in the war machine? Is this an action that will bear fruit, and would the same be true for all Americans?
I guess the alternative is to break the law by refusing to pay taxes? Or to become a monk so that the payment of taxes is not an issue? For the overwhelming majority of the householder population, things like taxes and death are unavoidable. Merely by existing in society, one contributes in an unavoidable way to suffering. Even if you are a vegetarian, when you pay for your vegetables, part of your payment may go toward the wages of an employee who is not a vegetarian, and who then uses that income from you to buy meat at the butcher shop, so you're still indirectly supporting the slaughter of animals. No matter what we do, from the moment we are born in ignorance we participate in this samsara until we are fully liberated.
All right, I don't know if that addresses your questions, but maybe it will spur a better response from someone else.