The EU thing isn't about sanctions, it's about having a mechanism in place that places a tariff on goods from countries that don't have similar costs attached to their carbon output.
From their point of view it is to ensure their goods, which are exposed to such costs, aren't put at a disadvantage as compared to goods from countries where they aren't.
They won't be the only ones to do so. The US and China both have shown they have no qualms with using tariffs to achieve domestic ends, I think we are entering a new phase of world trade where protectionism isn't such a dirty word, as long as it can be sold as not being for protectionist' sake.