Not many weeks ago I attended a presentation at the Prescott Library given by Sisters Carol Gilbert and Ardeth Platte. For the last 40 years, the two Dominican nuns have been working to achieve global nuclear disarmament. As part of a delegation to the United Nations from the International Campaign to Abolish Nuclear Weapons (ICAN), they were instrumental in creating The UN Treaty on the Prohibition of Nuclear Weapons. Seventy countries (not including the U.S. or Russia) have signed and 21 of 50 ratifications required to make it official have been completed thus far.

Carol and Ardeth have made nuclear disarmament their life’s work and have served substantial terms in federal prison as a result of their activist demonstrations. Needless to say their commitment to the cause is profound and unflagging, regardless of the fact that Carol is in her 70s and Ardeth in her 80s.

So when I heard that the U.S. has withdrawn from the Intermediate-range Nuclear Forces (INF) treaty, my thoughts went to the two gray-haired nuns and how this news must impact them. They must feel that one of the major steps forward in their life’s mission has now taken two steps back, as Russia also withdrew from the treaty in retaliation.

In reporting about latest INF developments, some news outlets included a clip of Ronald Reagan and Mikhail Gorbachov signing the original pact. As I watched, it seemed clear that, whatever their respective geopolitical pressures and motives, these two men had come to a personal truce as well as a global one. Neither seemed beholden to the other, they were simply in agreement. This was exemplified by Reagan’s comment, which he first spoke in Russian and then translated into English: “Trust but verify!”

Both men laughed heartily at this, but the simple phrase contained a serious truth. To enter into a meaningful agreement, there must be an assumption of the good will of all parties as well as some standard for adherence to the terms. It doesn’t mean that one or the other party will never violate the standard, but it provides a method for calling the violator to account.

The events leading to the collapse of the INF began with Russia first violating the treaty. U.S. ultimatums were not sufficient to rein it in and leveraging support from allies was apparently not an option. Moves to disempower NATO and antagonize long-standing allies like Canada, England and France have undermined faith in U.S. solidarity with the world’s democracies. Reneging on previous agreements (Paris Climate Accords, NAFTA ,the Iran Nuclear deal) and leaving the Baltic states hanging in the shadow of renewed Russian aggression, cast doubt on whether the U.S. still occupies the moral high ground.

This latest withdrawal begs the question, can America flourish by divorcing itself from the global community and becoming militarily unassailable, a fortress isolated within its own borders? Not only is that scenario improbable in the face of global realities, it leaves struggling democracies adrift, without the moral leadership and material support required to fend off authoritarian — and nuclear — assaults on their way of life.

The INF treaty was a ground-breaking step toward a safer world and deserved to be defended with every possible diplomatic means. Instead the U.S. government chose a simplistic tit-for-tat approach. Strong alliances as well as a nuclear-free world depend on both a healthy level of trust and a reasonable degree of skepticism. In his characteristically charming way, Reagan clearly stated the ideal middle path for the U.S. to follow in the world: “Trust but verify.”

I think Carol and Ardeth would agree.