As U2 was recording The Joshua Tree in 1986, the bandmates were firmly in their Americana phase. The Unforgettable Fire dealt with American icons such as Elvis Presley and Martin Luther King Jr. and now U2 was delving into the country’s roots music – blues, folk and gospel.

But The Joshua Tree wasn’t solely a celebration of the United States and its culture. It could also be an exploration of some of the ugliest American by-products. Nowhere was that more evident than on the LP’s fourth track, “Bullet the Blue Sky.”

The song was inspired by frontman Bono’s visit to El Salvador with Amnesty International in 1985, in the midst of the Salvadoran Civil War. The singer wasn’t only disturbed by the violence that he was learning about, but also by the fact that the United States Army was aiding and funding one of the sides as an attack on communism. The same visit also brought about “Mothers of the Disappeared.”

“I don’t think we were in danger, but I knew there were lives in danger or being lost close to us, and I felt for them,” Bono said in the Rock and Roll Hall of Fame exhibit, Louder than Words: Rock, Power and Politics. “It upset me as a person who read the Scriptures, to think that Christians in America were supporting this kind of thing, this kind of proxy war because of these Communists.”

As a man of faith, Bono began writing lyrics that employed Biblical imagery to describe what he had witnessed. “Bullet the Blue Sky” includes lines that recall Jesus being nailed to the cross and Jacob wrestling with an angel. However, another lyric was written with a then-current politician in mind. He talked about the man with a “face red like a rose in a thorn bush.”

“He’s peeling off those dollar bills, slapping them down – paying for the war,” Bon said. “He in my head was Ronald Reagan. I had not a sophisticated understanding of what was going down, but as a student of non-violence I had a violent reaction to what I was witnessing.”

Bono attempted to impart his reaction to his bandmates when Adam Clayton, Larry Mullen Jr. and the Edge began to record “Bullet the Blue Sky” for The Joshua Tree. The other three musicians in U2 sought to channel the frontman’s anger in a thunderous rock track.

“When I explained to Edge what I’d been through in El Salvador, he was able to, with nod to Jimi Hendrix, try and put some of that fear and loathing into his guitar solo,” Bono said. “We strapped my feelings to the song ‘Bullet the Blue Sky.’”

Although there was some consternation about how the anti-American song might be perceived in the States, “Bullet the Blue Sky” didn’t draw much controversy when it was included on The Joshua Tree. Although not issued as a single, the song quickly became a raucous tour highlight. The lyrics also gave the title to U2’s 1988 concert film and subsequent album (the live/studio hybrid Rattle and Hum).

Over the years, U2 has continued to play “Bullet the Blue Sky” in concert, often tailoring the political message to additional struggles via a visual display, taking on Nazism and consumerism, gun control and the refugee crisis in Europe. Wars end, new crises begin, and “Bullet the Blue Sky” continues.

Read More About 'Joshua Tree' Songs

"Where the Streets Have No Name"

"I Still Haven't Found What I'm Looking For"

"With or Without You"

"Running to Stand Still"

"Red Hill Mining Town"

"In God's Country"

"Trip Through Your Wires"

"One Tree Hill"

"Exit"

"Mothers of the Disappeared"

U2 Albums Ranked in Order of Awesomeness