I'm not an expert in trade law, but that's why I've mentioned this ozone-depleting substances tax that the U.S. introduced. They had a domestic tax on ozone-depleting substances and wanted to make sure their industries weren't at a competitive disadvantage to imports. That was considered to be acceptable under the GATT at the time, I think, not the World Trade Organization.
If it's acceptable, you're not subject to countervailing duties, right? It's legitimate under international trade law. So obviously you have to make sure that any arrangement satisfies international trade law, but there's a precedent out there for that.