The Senate is poised to approve new legislation that would hand President Donald Trump ammunition he could use to erode the 2015 nuclear deal with Iran, despite the fact that the agreement is working and that keeping it intact benefits U.S. national security.

Currently Iran is complying with the restrictions established by the nuclear deal and, so far, the United States is meeting its commitments to waive certain sanctions against Iran. Last month, U.S. Secretary of State Rex Tillerson formally certified to Congress that Iran is abiding by its obligations under the deal, and the May 17 announcement from the Trump administration renewing U.S. sanctions waivers is a de facto recognition that the Iran nuclear deal is working.


An Iran sanctions bill co-sponsored by Maryland Sen. Ben Cardin is currently making its way through the Senate, however. A vote in the Senate Foreign Relations Committee could come within days. If approved in its current form, the bill could undermine the nuclear agreement between Iran and six world powers.

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.

The Iran sanctions bill would also rewrite a U.S. commitment to remove certain restrictions in the future by requiring sanctioned entities to meet an additional certification. If Congress adopts this bill and President Trump signs it, it could open the door for Iran to accuse Washington of violating its commitments and redefine its own commitments under the nuclear accord. That is a slippery slope Washington would do well to avoid.

Given that Iran is currently complying with the restrictions on its nuclear activities, moving forward on legislation that risks these accomplishments makes little sense. It is in U.S. interests to keep the nuclear agreement intact and avoid actions that undermine the agreement and undercut Washington's multilateral partners in the deal.

For these reasons, a number of former U.S. officials, including the Iran deal's chief U.S. negotiator, Ambassador Wendy Sherman, oppose the legislation. Ms. Sherman said on May 16 that she supports pushing back on Iran's destabilizing activities but opposes the current sanctions bill "categorically" because of the risk it poses to the nuclear agreement.

Without question, Iran's activities in the Middle East region are troubling and destabilizing. Even though the nuclear deal significantly reduces the potential threat posed by Iran's missiles, Tehran's decision to continue testing ballistic missiles also runs contrary to UN Security Council measures calling on Iran to cease such activity. The United States can and should push back against these actions, and sanctions can be part of Washington's approach toward Iran. But sanctions that jeopardize the nuclear deal are not, on balance, worthwhile.

The nuclear deal did not sign away Washington's ability to sanction Iran for non-nuclear activities. Former President Barack Obama and President Trump have both used existing authorities to sanction Iranian entities involved in its ballistic missile program. But in using existing authorities to sanction Iran, or when pursuing new sanctions, it is critical that the White House and Congress consider the impact on the nuclear deal.

As a co-sponsor of the bill and the highest-ranking Democrat on the Senate Foreign Relations Committee, Senator Cardin has a responsibility to ensure that this legislation does not compromise Washington's ability to meet U.S. commitments under the agreement. Pushing back against destabilizing activities is appropriate, but doing it at the expense of an agreement that is removing the existential threat of an Iranian nuclear weapon, is irresponsible and dangerous.

Kelsey Davenport ( is the director for nonproliferation policy at the Arms Control Association, where she provides research and analysis on the nuclear and missile programs in Iran, North Korea, India, and Pakistan and on nuclear security issues.