Governor Andrew Cuomo’s remarks to the National Guardsmen and Guardswomen he has just called up against the coronavirus offer a rare moment — an early signal of how a political leader might comport himself in a military situation as commander-in-chief of the entire country. What Mr. Cuomo delivered over the weekend at the Javits Center in Manhattan was a classic of the genre.

The governor spoke before a group of guardsmen and guardswomen. The vast Javits building is due to open Monday as an emergency facility with a thousand beds for those stricken with the coronavirus. The hospital was organized in record time by, among others, the Army Corps of Engineers and the Guard. Mr. Cuomo began by praising to the guardsmen the generals who will lead them.

Then he turned to the rank and file, who, dressed in combat fatigues, were seated in folding chairs six or more feet part and told them: “This is a different beast that we’re dealing with. This is an invisible beast. It is an insidious beast. This is not going to be a short deployment. This is not going to be that you go out there for a few days. We work hard and we go home. This is going to be weeks and weeks and weeks.”

“This is,” he continued, “going to be a long day and it’s going to be a hard day, and it’s going to be an ugly day, and it’s going to be a sad day. This is a rescue mission that you’re on. The mission is to save lives. That’s what you’re doing. The rescue mission is to save lives and as hard as we work, we’re not going to be able to save everyone. And what’s even more cruel is this enemy doesn’t attack the strongest of us. It attacks the weakest of us.”

“It attacks our most vulnerable which makes it even worse in many ways. Because these are the people that every instinct tells us we’re supposed to protect. These are our parents and our grandparents. These are our aunts, our uncles. These are a relative who was sick and every instinct says protect them. Help them, because they need us. And those are the exact people that this enemy attacks.”

Forgive the long quotes, but his remarks were riveting. Then the governor said that every time he’s called out the Guard, he has made the same promise: “I promise you I will not ask you to do anything that I will not do myself.” He added that “the same is true here. We’re going to do this, and we’re going to do this together.” Then he told the guardsmen they they are “living a moment in history.”

This, Mr. Cuomo told the guardsmen, is going to be one of those moment they’re going to talk about for generations. “Ten years from now, you’ll be talking about today to your children or your grandchildren and you will shed a tear because you will remember the lives lost. You’ll remember the faces, and you’ll remember the names, and you’ll remember how hard we worked and that we still lost loved ones. And you’ll shed a tear and you should because it will be sad.”

Here the governor paused slightly and signaled with his hand. “But,” he said, “you will also be proud. You’ll be proud of what you did. You’ll be proud that you showed up. You showed up when other people played it safe. You had the courage to show up. You had the skill and the professionalism to make a difference and save lives. That’s what you will have done. At the end of the day, nobody can ask anything more from you. That is your duty.”

As we listened to the governor, we thought of our own generation, when the National Guard was — wrongly, but often — seen as an escape hatch from the Vietnam draft. Eventually thousands of National Guard troops were called up and appeared in arms honorably, even heroically against the communist forces in Vietnam. So Mr. Cuomo also reminded a new generation of what the National Guard, the organizing of which began in 1636, is made.