U2 became the biggest rock band in the world 30 years ago with the release of “The Joshua Tree,” the landmark album that transformed the Irish rockers from cult heroes to stadium-filling superstars.

To commemorate the anniversary, U2 is returning to stadiums to perform “The Joshua Tree” in its entirety. But the Rock and Roll Hall of Famers insist that the massive tour, which stops at MetLife Stadium on June 28 and 29, is not steeped in nostalgia, but actually reflects the times and where the band stands creatively today.

“That record was written in the mid-Eighties, during the Reagan-Thatcher era of British and U.S. politics,” U2 guitarist The Edge told Rolling Stone. “It was a period when there was a lot of unrest. . . . It feels like we’re right back there in a way. I don’t think any of our work has ever come full circle to that extent. It just felt like, ‘Wow, these songs have a new meaning and a new resonance today that they didn’t have three years ago, four years ago.’ ”

The songs from “The Joshua Tree” do seem eerily effective at describing the world in 2017, maybe even more effectively than they did in 1987. While “Bullet the Blue Sky” was inspired by Bono’s rage at what he saw as American policies in Central and South America that helped put authoritarian leaders in Chile, Nicaragua and El Salvador, the song certainly applies to how Syrian president Bashar al-Assad is attacking his own people, creating millions of refugees. The struggles of coal miners in “Red Hill Mining Town” have once again moved to the forefront of political discourse. The Dublin heroin epidemic outlined in “Running to Stand Still” has returned and expanded to America’s opioid crisis of 2017.

However, the emotions conjured up from “The Joshua Tree,” especially in its biggest hits, are even more recognizable today. The inspirational, chiming anthem “Where the Streets Have No Name,” about finding peace in the midst of trying times, when “we’re beaten and blown by the wind, trampled in dust,” feels like the search for a respite from the constant barrage of social media. The gospel-steeped “I Still Haven’t Found What I’m Looking For” continues to describe how the accumulation of things and experiences can still not be enough to provide contentment. And “With or Without You” remains one of the most haunting expressions of the destructiveness of love, Bono’s pain expressed both by the chant of “You give yourself away” and by his howls.

The success of “With or Without You,” which hit No. 1 for three weeks in the spring of 1987, marked a shift in how U2 was perceived. Bono, The Edge, bassist Adam Clayton and drummer Larry Mullen Jr. were no longer outsiders rebelling against the shallowness of the mainstream. They were the mainstream — bringing their political views, protests and personal issues with them.

advertisement | advertise on newsday

But that didn’t last long. It couldn’t. Until “The Joshua Tree,” U2 had been idealistic and, for lack of a better term, innocent. When superstardom arrives, a certain amount of self-preservation and guardedness has to come with it. And U2 soon began its cultural explorations that allowed them to make music without revealing as much about their personal feelings.

In recent years, the interplay between innocence and experience has become the band’s central focus, starting with the release of the “Songs of Innocence” album in 2014 and the “Innocence and Experience” tour that followed. “The theme of ‘Innocence and Experience’ has a line from a song called ‘Rejoice’ which is ‘I can’t change the world, but I can change the world in me,’ ” Bono told Rolling Stone. “I wrote that at 22. That’s the spirit of ‘Innocence.’ But the spirit of ‘Experience’ is actually I can change the world, I can’t change the world in me. That is the actual, dare I say it, dialectic of ‘Innocence and Experience.’ ”

On the current tour, it is once again a balance of innocence and experience as U2 starts with a set of songs leading up to “The Joshua Tree” before playing the album in its entirety and then a third set featuring more recent songs. Bono has said that many who are grieving the outcome of the American election and the British Brexit vote are grieving their loss of innocence. The answer, which is also one of “The Joshua Tree” lessons that applies to today, may be to embrace more experience.

“It’s OK to realize it’s going to be difficult, but we can do things,” Bono said. “We are full of ingenuity. The world can be a much better place, but don’t think it will be on its own. That’s the thing.”