Sam Nunn, a Democrat from Georgia, was a member of the U.S. Senate from 1972 to 1997. Ernest J. Moniz was U.S. energy secretary from 2013 to 2017. They are co-chairmen of the Nuclear Threat Initiative.

As Congress returns from its August recess, U.S.-Russia relations are in a deep ditch. This is a serious challenge for our governments and a danger to the people of both nations and indeed the world. Getting to safer ground requires urgent action to establish close cooperation between the Trump administration and Congress — by creating a new bipartisan liaison group modeled on one established in the 1980s.

Congress has legislated its outrage over Russia's interference in our election and its actions in Ukraine. Congress has also made clear its distrust of the president's handling of relations with Moscow. Legislation passed overwhelmingly in both houses (and reluctantly signed by President Trump) codifies existing sanctions, enacts new ones, and prevents the president from altering or removing the sanctions without congressional review and — for all intents and purposes — approval. This creates a joint responsibility between the executive and legislative branches. The challenge is to make it work to avoid a further downward spiral in U.S.-Russia relations.

Congress must assume responsibility for the authority it has asserted. This starts with the recognition that adjusting sanctions must not become such a difficult procedure that it hamstrings our foreign policy in dealing with Russia — which, as the other nuclear superpower, shares with us responsibility for reducing the risk of a nuclear weapon being used by nations or terrorists. If Russia concludes that economic sanctions are essentially permanent, its incentives for adjusting to a more positive course will be greatly diminished. Moreover, most Russian sanctions have been jointly adopted and implemented in close cooperation with our European allies — who may balk if faced with a congressional process that casts doubt on the prospects for sanctions to be lifted or modified.

With both the White House and Congress having a hand on the steering wheel for Russia policy, perspective at both ends of Pennsylvania Avenue is crucial. Congress must organize itself to be a constructive player, and the Trump administration must acknowledge this reality by reaching out.

A liaison group, which could include the chairs and ranking minority-party members of key committees from both houses of Congress, should be appointed by congressional leadership to work closely with the administration to receive briefings and offer constructive feedback. The closest Cold War parallel is the Senate Arms Control Observer Group established by Sens. Robert Byrd (D-W.Va.) and Bob Dole (R-Kan.) to communicate regularly with Secretary of State George Shultz and the arms control negotiators during the Reagan era. It worked, thanks to sustained focus by members of Congress and unprecedented cooperation with the State Department and the White House.

The group coordinated continuously and carefully, and the treaties that were eventually submitted received widespread support and helped manage and eventually end the Cold War. Today, we need to create a similar framework so Congress can maintain effective oversight and accountability while providing political space and support for the administration to pursue meaningful U.S.-Russia discussions on vital interests — and adjust course, if warranted.

Reestablishing a workable consensus on Russia policy between Congress and the Trump administration is also essential to maintaining cohesion and close coordination with our European allies. At a time when Europe is receiving mixed messages from the president and Congress on the direction of Russia policy, the liaison group could help underscore to European governments that Washington — both Congress and the president — understands and supports not only Europe's essential role in implementing sanctions, but also our shared interest in improving security in the European Atlantic region.

Finally, Washington and Moscow must recognize that despite their deep differences, there is an urgent need to address areas of common interest, chief among them reducing nuclear and other military risks and preventing catastrophic terrorist attacks. We had ongoing dialogue about nuclear risks during the Cold War, and the lack of it today is dangerous. These are discussions the liaison group could constructively shape and support, displaying U.S. governmental unity. Over the longer term, the liaison group could also provide a foundation for dialogue with parliamentary counterparts in Russia.

One thing is certain: Inaction and continued dysfunction between the executive and congressional branches of our government will make it even more difficult to put out the intense fires we now face in many parts of the globe. Reestablishing close cooperation between the White House and Congress through a liaison group is an essential prerequisite to renewing cohesion with NATO and our European partners — and effective communication between Washington and Moscow on our vital mutual-security interests. It is imperative that we address the U.S.-Russia relationship on critical nuclear-security issues to avoid miscalculation that could escalate into existential threats to both countries.