On the anniversary of John Lennon's murder (Dec. 8, 1980), I've been thinking about his famous argument with Gloria Emerson in December, 1969 – filmed by the BBC, and included in the recent documentary The U.S. vs. John Lennon.

Emerson was a celebrated war correspondent for the New York Times who had just returned from the bloody battlefields of Vietnam; Lennon had just written "Give Peace a Chance" after he and Yoko declared their honeymoon a "bed-in for peace"–they had stayed in bed for a week, "in protest against all the violence in the world."

Emerson told him in her haughty upper class voice, "You've made yourself ridiculous!"

"I don't care," Lennon replied, "if it saves lives."

"My dear boy," she said, "you're living in a nether-nether land. . . . You don't think you've saved a single life!"

"You tell me what they were singing at the Moratorium," Lennon shot back – he was referring to the biggest anti-war demonstration in American history, which had been held in Washington DC a month earlier.

Emerson wasn't sure what he was talking about: "Which one?"

"The recent big one," Lennon explained. "They were singing "Give peace a chance."

"A song of yours, probably."

"Well, yes, and it was written specifically for them."

"So they sang one of your songs," she said with some irritation. "Is that all you can say?"

Now he was angry. "They were singing a happy-go-lucky song, which happens to be one I wrote. I'm glad they sang it. And when I get there, I'll sing it with them."

The film presents the exchange as an example of the mainstream media's relentless hostility to Lennon's peace activism, and celebrates his put-down of Emerson. But 37 years later, it's worth reconsidering Emerson's question: did "Give Peace a Chance" save a single life? Did the anti-war protest of 1969, or any other year, save any lives?

Of course the Vietnam war didn't end in 1969, even though Nixon had been elected the previous year after declaring he had a secret plan for peace. The Paris Peace Talks were already underway, but the American war didn't end for another four years – during which 20,000 Americans were killed, along with more than half a million Vietnamese and Cambodians.

You might ask Gloria Emerson's question about the anti-war demonstrations on the eve of the Iraq war, in New York, Los Angeles, London, Rome, and elsewhere. They were the biggest anti-war demonstrations in world history, but Bush invaded Iraq the next month anyway, and as of Dec. 8, 3,000 Americans have been killed there, and perhaps 650,000 Iraqis, according to the Johns Hopkins study published in The Lancet. Did those demonstrations in 2003 save a single life?

Maybe not, or at least not yet. Stopping a war takes a long time. But apathy in the face of an unjust war is simply unacceptable. As Rebecca Solnit argues in Hope in the Dark, you have to keep trying to win people over, because you can never be sure the forces of darkness will triumph, and because the most impossible things sometimes happen.

Lennon did come to the US, and eagerly embraced the steady work of anti-war persuasion and organizing. "Our job now is to tell them there still is hope," Lennon said at an anti-war rally in Michigan in 1971. "We must get them excited about what we can do again." It was hard to see it in 1969, but eventually the US did end its war in Vietnam. And today the people who were singing "Give Peace a Chance" in 1969 can be glad they sang it.