Wow. This has to be one of the most interesting questions ever asked on the forums. Unfortunately, my realistic side kicked in after a few seconds of euphoria, imagining the peaceful possibilities. Even if it is true that no two nations where salsa is a predominant musical style have ever declared war on each other, that alone isn't proof that salsa=peace. You can declare war on your own people just the same, like Trujillo, the former dictator of the Dominican Republic who was a HUGE merengue fan. Or, like a long string of US-puppet dictators in Cuba who supported comparsa, son, danzon, cha-cha-cha, and other popular styles (I'd mention another loser too, Fidel Castro, but it's well documented that he doesn't care for music very much). Or, like all the corrupt loser politicians in Colombia (home to some of the world's greatest salsa) who sell their soul, their people, and their country out to the interests of the drug cartels.
But still, it's a question worth considering. In my collection I have mostly salsa/Latin but I have a fair amount of Rai (an Algerian secular music that originated in brothels but moved on to become a popular music of the people, then was banned by Algerian Islamic extremist goverment, after which Rai music moved with Algerian exiles to France), popular African styles, Some Turkish pop from Tarkan and others, and a fair bit of Bhangra from India, etc., and I always marvel at how well those styles relate to each other. I also marvel at how people who love salsa music usually take well to those other types of music, and that makes me think that there's a potential there for understanding that leads to an appreciation of other cultures and therefore to peace.
And, once again, who are the people who don't like music and dancing? Fidel Castro, who has made himself a religion, the Taliban, for instance, the Algerian extremists who banned Rai music and even assiniated one of the biggest Rai stars, Cheb Hasni, in 1994, John Ashcroft (someone here on the forums used to have a great anti-dance quote from Ashcroft, something about how dance is the devil's palsy), and other religious wackos. They are the biggest problem we face, I think.
In Dubai, the United Arab Emirates, I hear that you can dance to salsa seven nights a week. It's also the most liberal, and most economically developed country in the Middle East. It's like Hong Kong on the Arabian Gulf. They've also got most of the crazy Islamic fundamemtalists in check, even though it is still an Islamic country with Islamic rules. But still, salsa is very popular there. There's definetely something to that, something very important.