Joe Biden has made no secret of his intention to get us back into the Paris climate accords. It’s high up there on his laundry list of things to do upon taking office—even though the United States leads the world in reducing carbon emissions, despite not being a part of it anymore. But the truth is, the United States was never actually legally a part of the Paris climate accords. The United Nations describes it as “a legally binding international treaty on climate change,” and it also meets the definition of a treaty under the Vienna Convention on the Law...