The bare minimum expected of a leader of the American left, and a democratic socialist, should be a willingness to say “I endorse the conclusion of mainstream human rights organizations.” Why wouldn’t Sanders be willing to do that? He says that it doesn’t really matter “what you call it,” because it’s horrific. But clearly it does matter to Sanders, because he is making a choice not to use the same language as the human rights organizations. Why is he making that choice? He has not explained.

Sanders is right that the more important debate is about actions rather than language. But genocide is also the supreme crime against humanity, and it is so unanimously reviled that it makes a difference whether we use the term. For instance: there might be a debate over whether we should cut off weapons to a state that has “engaged in war crimes.” (How many? Are they aberrations or policy?) The Allied powers in World War II engaged in war crimes, and many Americans think war crimes can be justified in the service of a noble end. But there can be no debate over whether we should ever arm a state that has engaged in genocide. Genocide has no justification, no mitigation. If a state is committing it, all ties should be cut with that state.

Actually, we can see the difference in Bernie Sanders’ own policy response to Israel’s crimes. He told CNN that “your taxpayer dollars” should not go to support a “horror.” This is true. Sanders, to his credit, has repeatedly proposed a bill that would cut off a certain amount of weapons sales to Israel. Democratic opinion has so soured on Israel that Sanders’ bill attracted a record amount of Democratic support (27 senators, more than half the caucus.) But notably, Sanders’ bill only cuts off “offensive” weapons to Israel, leaving “defensive” weapons sales intact.

We might think that it’s perfectly fine to sell “defensive” weapons. Israel’s “Iron Dome” system, which U.S. taxpayers help pay for, protects the country against incoming missiles, and protection against incoming missiles is surely a good and noble thing. But notably, we have not bought Hamas its own “iron dome.” Or Iran. Or Russia. This is because we do not support the causes for which they fight. We understand in these cases that to help the “defense” is to help the “offense.” If Russia is protected from Ukrainian missiles, it will fight Ukraine more effectively. Likewise, if Israel is protected from Hamas rocket fire, but Gaza is not protected from Israeli missiles, the balance of arms is tilted toward Israel, and they can pulverize Gaza without Hamas being able to inflict similar damage in response.