On my recent trip to Russia, I spent an hour with Mikhail Gorbachev. I told him that in the West we are grateful that he and President Ronald Reagan defied Cold War orthodoxy to significantly reduce our countries’ nuclear arms. And I asked him whether there was a moment in his life when he’d realized that he might shape history.

He paused a moment and then recounted how as a young man, he had watched a film on the devastation that would occur with nuclear war. He and the other young officials in the room looked at each other in shock as the film concluded.

Gorbachev recalled the scene: “Even though I am not a believer, I responded, ‘Oh my God!'” From that moment, Gorbachev said, he decided to use every opportunity that came his way to prevent a nuclear holocaust.

Gorbachev’s youthful concern about nuclear disaster became apparent when he assumed leadership of the Soviet Union. In a speech he gave to senior personnel of the Ministry of Foreign Affairs in May 1986, Gorbachev said, “Peace is the value above anything. In the nuclear-cum-space era, a world war is the absolute evil. It cannot be won.”

I asked Gorbachev about meeting Reagan for the first time. He said that their first meeting was affable but inconclusive. Press reports from the Reagan camp revealed that Reagan thought Gorbachev was just an old-school Bolshevik. Gorbachev remembered his response when his aides asked whether Reagan was just a hard-line anti-communist. Gorbachev chuckled and said, “No, he is a dinosaur!”

But both men persisted. Despite the Cold War atmosphere, rampant mistrust, and fearmongering on both sides, the leaders engaged each other. Ultimately, multiple agreements were hammered out, including the Intermediate-Range Nuclear Forces (INF) Treaty and the START treaty. Over a four-year period, the former eliminated nearly 2,700 missiles.

Over the years, though, agreements with Russia to reduce nuclear arms have not followed a straight path of success. Shortly after the 9/11 attacks, George W. Bush announced his intention to withdraw from the Anti-Ballistic Missile (ABM) Treaty. Russian President Vladimir Putin responded by announcing that the INF Treaty might no longer be in Russia’s interests. Russia had ratified START II in 2000 but pulled out of the treaty after the U.S. withdrew from the ABM Treaty.

Most recently, New START took effect in 2011. In addition to placing a cap of 1,550 on deployed strategic nuclear warheads, a nearly three-quarter drop from START, New START also cut in half the allowable number of strategic nuclear-delivery vehicles, such as missile launchers and heavy bombers.

New START expires in 2021. If either side allows it to simply sunset, it will be the first time in several decades that a nuclear-arms-reduction treaty between the U.S. and Russia lapses.

As our hour was coming to an end, I asked Gorbachev whether he had any words of wisdom to improve our current dialogue. “Bring the conversation back to nuclear-arms reductions,” he said. “Encourage both sides to restart talk of renewing the START and INF treaties.”

That echoed his public call last year:

    “If the INF treaty could be saved, it would be a powerful signal for the whole world that the biggest nuclear powers understand their responsibility

     and take their obligations seriously.”

Gorbachev argued then, as he did in our meeting, for a summit between President Donald Trump and Putin to discuss nuclear-arms control.

In my meetings with the foreign-affairs committees in Russia’s upper house, the Federation Council, and lower house, the State Duma, legislators also expressed an interest in holding formal talks to renew New START and continue the INF Treaty. I have invited members of both foreign-affairs committees to Congress this fall to continue these discussions. It is my hope that Democrats who have previously been supportive of nuclear-arms reductions will join in these meetings.

On the long flight home from Russia, as I was reading Eric Metaxas’s book Martin Luther, I realized that great challenges to orthodoxy are rare but necessary at times to right great wrongs or prevent great tragedy. I, for one, am thankful that Reagan and Gorbachev defied orthodoxy to cut stockpiles of nuclear weapons and reduce the tension between our countries. I hope thoughtful minds will prevail in our current standoff with Russia, and embrace the dialogue necessary to further reduce the potential for the terrible, world-altering catastrophe that a war between nuclear powers could bring.

The day after my meeting with Gorbachev, I visited Bunker 42, built by Stalin to survive a direct nuclear hit on Moscow. Each day, 600 people secretly descended about 180 feet below the streets of Moscow to a bunker protected by 10-foot-thick concrete. In the bunker, I watched a video recounting the nuclear-arms race, which culminated in Russia exploding a 50 megaton hydrogen bomb aboveground that destroyed everything within more than a dozen miles, with effects that could be felt and seen for hundreds of miles more. Likewise, in America, we built an elaborate bunker deep in the mountain adjacent to the Greenbrier resort in West Virginia. Today, thanks to Reagan and Gorbachev-two leaders brave enough to engage in dialogue-these bunkers are decommissioned and open to tourists.

My goal in visiting both government and opposition leaders in Russia is to promote dialogue. My hope on my return to Congress is that I will find bipartisan support for improved dialogue and continued progress on reducing nuclear arms.