While I agree with some of Richard Fein’s ideas in his Dec. 23 column about the need to negotiate an end to the Ukraine war [“Ukraine, Russia and a potential ceasefire”], he left out the most important reason for doing so. Continued escalation on the part of the U.S. and NATO — such as allowing Ukraine to keep firing our long-range missiles (ATACMS) deep into Russia — could lead to a direct confrontation with Russia.

That could easily lead to nuclear war, a catastrophe that would affect not just Ukraine and Russia but the whole world.

We do more than just provide Ukraine with these missiles; our military personnel assist with their targeting as well as the use of our satellites to guide them. That’s why the Russians consider these attacks as being carried out by the U.S., not Ukraine. And they are dangerous because they are unprecedented: In the past 75 years of the Cold War, first with the Soviets and then the Russians, neither side ever actually dropped a bomb on the other’s country.

Nearly three years into this war, with their significant advantages in manpower, weaponry and airpower, the Russians are gradually pushing the Ukrainian army back and taking more and more territory. Many retired military and foreign policy analysts (Daniel Davis, James Webb, Douglas Macgregor, etc.) think the Ukrainian military could soon face total collapse, opening the way for the Russians to take control of the entire eastern half of the country up to the Dnieper River.

Such a scenario is extremely dangerous if the U.S. and NATO try to prevent such a defeat by escalating the war, either by continued long-range missile strikes into Russia, or sending in European troops. Both are big red lines for the Russians. Another military expert who is sounding the alarm about this situation is MIT Professor Emeritus Ted Postol, a top nuclear weapons scientist and former adviser to the Pentagon.

He’s now a strong proponent of negotiating with the Russians to limit or eliminate nuclear weapons and end the expensive arms race. He warns that if Ukraine makes another attack on Russian early-warning radar systems, like it did last May when it damaged three out of 10, it could lead to an accidental nuclear war because the Russians might think they’re under nuclear attack by the U.S. and therefore launch their missiles first.

We simply can’t keep playing with this kind of unimaginable fire and testing the Russians with our escalations, thinking they’re weak and just bluffing. If there were any historians left on earth after a nuclear war to tell the story, they would decry the utter recklessness and folly of our military and political leaders who thought we could go on threatening each other but never use such doomsday weapons.

And they’d lament the powerful influence of the media that kept the public from understanding the dangers that were mounting, and from heeding the message of the recent hit film “Don’t Look Up.” Its fictional premise was of an asteroid bearing down to destroy the Earth, while it was really trying to alert the public to the growing risk of nuclear war.

Even if the worst-case scenario of nuclear war is avoided, Ukraine is still suffering huge losses in soldiers, energy and transportation infrastructure, territory, millions of refugees in Europe, environmental damage, and the lowest birth rate and highest death rate of any country in the world. Recent polls by Gallup and CBS found a majority of Ukrainians want a negotiated settlement of the war, even if it means concessions of ceding territory to Russia and not joining NATO.

The Ukrainian people are also so tired of this war that they don’t want to see their men literally dragged off the street and forced into the military in an increasingly desperate attempt to defeat the Russians. Many also don’t want their government to follow U.S. urging to drop the draft age from 25 to 18.

So contact President Biden in his final weeks, along with our congresspeople; urge them to act with courage like JFK in the Cuban missile crisis, and start negotiations for peace in Ukraine and for nuclear disarmament with the Russians. Our children and grandchildren’s future, and the world’s, depends on us.

John Berkowitz, a member of Massachusetts Peace Action’s Peace in Ukraine Campaign, lives in Northampton.