This past weekend, with the London papers full of the bombing of Afghanistan, I watched thousands of protesters streaming past Speaker’s Corner in Hyde Park. Coordinated by the suddenly resurgent Committee for Nuclear Disarmament, it was a portmanteau affair that mingled environmentalists, anti-globalizationists, socialists, communists, Northern Ireland activists, anti-Zionists and lots more. But on this warm spring-like day, there was a touch of nostalgia in the air. Some of the banners and slogans felt as though they had been tucked away in attics for decades. Yes, it was about peace. But in some ways, it felt more like a convenient airing of pent-up general grievances.

Later that day, I talked at length with six young Londoners – two Indian Hindus, an Indian Sikh, a Pakistani Muslim, a Northern Ireland Protestant, and an Englishman – all under 26 years of age. Here, too, something was different. They hadn’t marched – and agreed they hadn’t wanted to. They didn’t like the war, though they agreed the United States had to respond somehow. They criticized George Bush and their own prime minister, Tony Blair, though several admitted they would have liked to pursue careers in diplomacy. They were wary of government intrusion into their lives, but agreed that a stronger intelligence service was crucial.

As I listened to them talking, I was reminded of a conversation I’d had several weeks before with a caller on Wisconsin Public Radio. As a young man in the 1960s, he’d been sent to fight a war in Vietnam that he despised. Returning home, he become an ardent antiwar protester – and remained so until Sept. 11. That day, when the planes hit the World Trade Center, his response was almost knee-jerk: He rushed to his local National Guard post to reenlist. Why? Because, as he said, “this was different.”

As the military campaign polarizes opinion, we’re already seeing antiwar protests. But I suspect the new peace movement will be significantly different from the one I saw as a student at Columbia University during the late ’60s.

Why? Because there’s a different public attitude today, at least in America. Gallup notes that about 90 percent of the public supports retaliatory military action. President Bush, too, is hugely popular, with a 90 percent approval rating. And the U.S. public, rather than sinking into malaise, registers a higher reading on Gallup’s “Mood Index” than it did before the attack.

So what might this new peace movement look like? If it is to be successful in drawing popular support, it will need to move away from the ’60s stereotype of the flower child and become a more adult movement. That’s partly because this time the dead were not young male draftees but mature men and women holding jobs in the workaday world. What’s more, they weren’t killed when a government sent them into battle as soldiers, but when they were attacked as civilians.

Second, where the radical peaceniks of the past opposed not only belligerence but the entire idea of defense and military intelligence, this new movement will have to come together around a narrower goal: the protection of citizens in countries under retaliatory attack. It will condemn indiscriminate vengeance abroad. But it will find it difficult to object to increasing “homeland” security or a beefing up of intelligence to forestall further terrorism.

Third, and most important, this new movement will need to be less wedded to black-and-white distinctions. An earlier generation of peace advocates claimed to know exactly what was “good” (music, love, communal interactions) and “bad” (corporations, police, politics). This generation will need to comprehend the world in a more nuanced, multidimensional way. The rhetoric of “peace at any price” won’t resonate. There will need to be fewer cynical dismissals of government, diplomacy, and politics. It will be harder to make glib, moralizing diatribes against America as a place that gets it all wrong. To be sure, the new movement can and will criticize U.S. policy and culture. But unless it does so against a constantly recalled backdrop of outrage at the slaughter of civilians and of support for the values that the terrorists were attacking, it will remain a fringe movement.

Will the new movement be more fundamentally moral than its predecessors? Yes, if by “moral” is meant a capacity to examine the values-based arguments on both sides of a question and arrive at a balanced understanding. To be sure, it will have its own noisy fanatics. But at its core, it will only gain popular support if it resembles what in parliamentary democracies is called “the loyal opposition” – patriotism with a human face, a tough-love national pride.

That’s different. They didn’t talk that way in the ’60s.

Rushworth M. Kidder is the founder of the Institute for Global Ethics in Camden.