Besides the Beatles, no other band's or artist music is beloved by so many. Their music their name is popular on a global scale, for their reunion ticket 20 million people registered to get a ticket and crashed the system. The popularity as Led Zeppelin is on such a global scale, they are beloved of people of all ages.
This is such a long shot, and it really has nothing to do with LED Zeppelin reuniting for a world tour, but if there is any music, band, artist...etc that can possibly help bring about peace it is Led Zeppelin.
Ask them to do so if the world leaders worked their differences out and went about achieving world peace. It's not about money, it's not about LED Zeppelin getting together, but them helping bringing about peace through the power of their music.