The only groups I can imagine challenging the mining itself would be private environmentalist groups (and even then, of the environmentalists who care at all, t

The only groups I can imagine challenging the mining itself would be private environmentalist groups (and even then, of the environmentalists who care at all, this would still be a low priority), and they do not have standing to challenge it. In order for a state to care about challenging it, I suspect we would need to states to want to mine at the same location, in large enough quantities that they might get in each others way, or deplete the resource.