The morning after last weekend's Amnesty International concert, Jackson Browne seems amused at the suggestion that an American version of Latin America's overtly political Nueva Cancion (New Song) movement might be springing up. The idea that the tunes they are a-changin' had come from impassioned sets by Browne and Little Steven Van Zandt, as well as from the political statements made by others on apartheid, American intervention in Central America, the arms race and the Sanctuary movement.

"When you get a group of writers and singers known for their proximity to these issues, and then those artists limit their selections to songs appropriate for the occasion, it may seem like it," Browne admits.

"But I think what is happening is a very broad, general awakening" in the music fans as well as in the music business, he says. "It seems to be all right to talk about these things in a pop song now."

This from the quintessential introspective lyricist of the '70s, a romanticist whose plaintive songs always had an apocalyptic edge but whose best known social statement had been the yuppie-bashing of 1983's "Lawyers in Love," a man who a few years back told an interviewer there was "something about the big serious questions that does not make me want to sing."

On Browne's recent "Lives in the Balance" album, sharply etched political songs question cultural imperialism, foreign policy and the current state of the American dream. The very focus of the album was questions. In "For America," Browne asked: "The thing I wonder about the dads and moms/ Who send their sons to the Vietnams/ Will they really think their way of life/ Has been protected when the next war comes?" And on the title cut, he sang: "On the radio talk shows and the TV/ You hear one thing again and again/ How the U.S.A. stands for freedom/ And we come to the aid of a friend/ But who are the ones we call our friends . . . the governments killing their own?"

At 35, Jackson Browne, who performs tonight and tomorrow night at Merriweather Post Pavilion, seemed unwilling to keep living in what he himself called "the safety of my own head."

Of course, it's not as if Browne has been entirely self-absorbed since his debut album in 1972. He'd played at campaign fundraisers for California Gov. Jerry Brown's failed presidential campaign in 1976 and was a major organizer of the Musicians United for Safe Energy (MUSE) concerts in 1979. In fact, Browne spent most of two years working with the antinuclear movement, though he admits finding it "hard to sing about nuclear technology."

"What's changed in the last three years is my focus and attention," Browne explains. Soon after the "Lawyers in Love" album, he says, "I was in the middle of reading books about Vietnam and right at the end of that summer I picked up a book called 'Salvador' by Joan Didion. And the similarities and parallels . . . were inescapable. I was thunderstruck: Damn, this is happening again."

Browne started going to lectures and debates about American involvement in Central America and someone finally suggested "going to Nicaragua to see for myself. I went twice and I think this interest has been reflected in my music."

There was a practical inspiration to the new songs, as well. Browne remembered meeting with some Nicaraguan folk musicians in Managua. "I was sitting at a table with people who had lived through a revolution and were actively involved in the continuation of that revolution, and they were trading songs with a guitar," he says. "I had the first verse of 'For America' and that's really all I had. I could also sing 'For Everyman' and I did," but the experience made Browne aware of the limits of his own repertoire.

Soon after returning from the second trip to Nicaragua, Browne discovered Van Zandt's politically focused "Voice of America" album, which he calls "brilliant . . . one of the best of 1984 . . . What was great is that he had such a rock stance -- snakeskin vest and scarves and looking like a pirate -- but he was well read. He'd done his homework on these subjects that he was expressing with such fundamental rock purity. It just stood me on my ear . . . that was the encouragement."

Browne became more politically involved, participating in town meetings around the country, giving benefit concerts. He was a part of Van Zandt's "Sun City" record and video and has been actively involved in supporting the Sanctuary movement. He also sang Van Zandt's "Voice of America" for Haskell Wexler's "Latino," a stridently propagandistic film against U.S. involvement in Nicaragua. Wexler is uncle to actress Daryl Hannah, who happens to be Browne's companion of the last few years.

But Jackson Browne is a notoriously slow worker and the fruits of his growing political interests weren't evident to a larger public until "Lives in the Balance." The shift from personal to social issues seemed to bring his albums in line with his life.

"I know people who really sit down and write a song on a subject and I wish I could do that," he says. "But a song is almost like a residue in my life; they're left from experiences and from where I focus my attention . . . It's necessary to know yourself, to know where you want to go. Though if you limit yourself to that, you might as well be a hermit or a monk."

"There's a time to breathe in and a time to breathe out," he told Musician magazine. The political and the personal life -- so often pictured as opposites -- "do coexist," Browne says. "They coexist in life; why shouldn't they coexist in a person's work?

"Every time I do something recently, that's all I hear, how much I've 'changed,' " he says in exasperation. "I always thought it was an artist's first duty to grow, so I'm happy about that. The world is changing and you change with it."

Still, he says, an artist's speaking out on social issues is not a responsibility but "an opportunity.

"I'm not sure what I'm going to write next. I had some other songs written that didn't seem to be part of the same album. But there are a couple of 'personal' songs about relationships. Those are lives in the balance too, and that's sort of a unifying thing."

The responsibility is "giving you information and allowing you to make your own deductions. I don't think people want to be preached to, but information is important," Browne says. "The American public is so isolated from the rest of the world . . . So much is done in their name in the rest of the world with their tax dollar that they're unaware of. I think Americans are decent and generous and I think that if they really knew all that's done in the name of our freedom, they would be outraged."

Songs from black spirituals to Verdi operas have been political messengers of their eras, but the political side of rock, Browne says, is "something of a time bomb. Rock 'n' roll is a world language . . . A song is something that gets repeated, it has reverberations. It can be recalled, unlike most speeches. Speeches are not televised again and again." Songs "can be very influential.

*"I don't feel people want to be preached to. And that's not my job. What people need is information and what music can do is connect people or talk about things that everybody feels. That's what Steven's album did for me. It really meant a lot that somebody was talking about these things. I had no idea he was concerned with any of that, and it was a relief and an encouragement."

But does all this risk alienating fans of the traditional Jackson Browne sound?

"It's all relative. If there's some sort of commercial risk, it's not as important as many other risks that people can take," he says. "It's not the kind of risk that people take on their Christian beliefs in Tucson in the Sanctuary movement."

On one song on his new album, Jackson Browne sings, "I'm not gonna shut my eyes/ I've already seen the lies/ On the faces of the men of war/ Leading people to the killing floor/ . . . Till I go down . . . I'm not gonna shut my mouth."

"That's a promise not to fall asleep, not to give up because you think it's hopeless," he says passionately. "Not to be bought off by the wonderful things you can have in this country that divert your attention. Many of the things that are done in the name of our glorious idealism and our fat life style are very harmful to the world at large and particularly deadly to innocent people." "There's only so much information you can get out in a song," he adds, "but a song is an emotional thing. And if it leads people to get information, then it's a powerful tool."