I don't buy your defeatism at all. The US certainly has the economic clout to make progress, and there's certainly a middle ground between doing nothing and exp

I don't buy your defeatism at all. The US certainly has the economic clout to make progress, and there's certainly a middle ground between doing nothing and expecting that every attempt to regulate externalities must be 100% effective and 100% enforced on every economic actor. At some (usually reasonably achievable) point, compliance becomes cheaper, or substitution occurs.