> "If you're an American, your comfortable life exists because of the American government's willingness to inflict violence on other people to maintain our status in the world"
There are few alternatives with our current technology, if the american way of life is not to be negotiated, so let's leave that aside. In any case, when north america becomes self sufficient again or even a net exporter of energy, things will change.
OTOH, for diamonds, there does not seems to be any change in sight. They are a massive hypocrisy, with the huge negative externality of fuelling wars and human misery - and they are controlled by a monopolist!
I'm sorry maybe I'm too heartless and an economist in the soul, but I just can't dig this idea. Diamonds are awful in any way I can see them. And I miss my life partner because of this IT WILL BE A GOOD THING: better splitting up early : both the costs and the emotional attachment will be lower.
EDIT: you talk about taking a train, walking, relocating - that's not acceptable for most people; also it will cause them undue burdens. Replacing a shiny rock by a purer shinier rock is possible and simple. It just requires some cultural or legal changes (think bald eagle feathers) which seems already underway.