The Trump administration has refused to implement new sanctions on the Russian defense sector, as mandated by Congress’s “Countering America’s Adversaries Through Sanctions Act,” or CAATSA. Congress passed the bill last year and it was reluctantly finally signed by Trump in August. It is vaguely worded enough, however, that Trump’s White House attorneys appear to have concluded that it need not actually be implemented.

The question of whether US sanctions on Russia, or further such sanctions, are wise or justified or even legal can be argued. But Trump’s actions in this case are flatfooted and will give rise to further suspicions that Putin has some sort of hold over him. He could have declined to sign CAATSA on any number of grounds. Or he could have implemented it half-heartedly. Signing it and then not implementing it is the worst of all possible worlds politically.