"War Is Over! If you want it" – a full page ad in the Sunday New York Times Dec. 27 must have puzzled many readers. The ad marked an anniversary: it was 40 years ago today that John Lennon and Yoko Ono launched their "War Is Over!" campaign, with billboards in New York, London, Hollywood, Toronto, Paris, Rome, Berlin, Athens and Tokyo proclaiming the message in giant black letters on a white field – and in much smaller type at the bottom, "Happy Christmas, John and Yoko." The message was repeated on posters, leaflets, and newspaper ads.

The war in Vietnam was reaching a climax that month as American deaths reached 40,000. And the anti-war movement also reached a climax: Nov. 15, 1969, 250,000 people marched in Washington D.C. in the largest anti-war demonstration in the nation’s history. At the Washington Monument, Pete Seeger led the demonstrators singing Lennon’s new song, "Give Peace a Chance."

Now that the US is at war in Iraq and Afghanistan, the campaign is being brought back to life by Yoko – with a new twist: "War Is Over!" will be appearing, among other places, on the ad displays on top of 160 taxis in New York City for the month of January — a project of the nonprofit Art Production Fund.

And Yoko also posted a 1969 "War Is Over" video at YouTube — and online, downloadable do-it-yourself posters in 60 languages.

Lennon’s 1969 campaign began with a "War Is Over!" benefit concert for UNICEF at the Lyceum Theater in London, John’s first live performance in England in four years. George Harrison, Eric Clapton, Billy Preston, and Keith Moon of The Who joined him onstage.

Not everyone understood John and Yoko’s "War Is Over!" campaign. John Sinclair, the Michigan antiwar activist and White Panther leader who would soon be sentenced to ten years in prison for selling two joints to an undercover cop, declared, "You are going to sound awfully fucking stupid trying to tell the heroic Vietnamese people that ‘the war is over if you want it’ while they are being burned and bombed and blown out of their pitiful little huts and fields."

Sinclair of course had missed the point; the campaign was directed at the American people, not the Vietnamese. "You’ve got the power," Lennon told young Americans in an interview. "All we have to do is remember that: we’ve all got the power. That’s why we said ‘war is over if you want it.’ . . . . Don’t believe that jazz that there’s nothing you can do, ‘just turn on and drop out, man.’ You’ve got to turn on and drop in. Or they’re going to drop all over you."

Dec. 31, 1969 – 40 years ago this week – BBC-TV featured John as a "Man of the Decade." "The sixties were just waking up in the morning," he said. "We haven’t even got to dinnertime yet. And I can’t wait! I can’t wait, I’m so glad to be around."