As currently written, this bill imposes new, vague and overly broad sanctions on entities involved in ballistic missile development that could trip up companies and banks pursuing legitimate business in Iran as permitted by the nuclear deal. And in the hands of a president with poor impulse control who has threatened to rip up the nuclear deal in the past, the power to impose sanctions under vague authorities is a free pass for Mr. Trump to erode the agreement under the guise of congressional support.