The idea of touring on The Joshua Tree this year came from the band's belief that the themes of the album still resonate today.
When I saw U2 in concert 25 years ago, Bono gave a short speech before "I Still Haven't Found What I'm Looking For" about his love of America and how important it is for Americans to get informed and make smart choices in our upcoming (1992) elections, "because, let's face it: if you screw it up, we're all ####ed."
I don't know if Bono did this last night, but on other tour stops he's talked about Ireland's kinship with America, how they are both lands of Dreamers, America's past history of welcoming Irish dreamers seeking a new start, and how America is so much more than a country; it's an idea, one of the best ideas we humans have ever had.