The Fresco by Sheri S. Tepper
Benita Alvarez, a downtrodden Hispanic woman, is chosen by the alien envoys Chiddy and Vess to be the Intermediary in their bid to get humankind to join an interstellar federation of peaceable races who practise Neighbourliness and strive to live ethical and moral lives. They have their own ways of showing us where we're going wrong: in short order they disappear Jerusalem until the Middle East learns to live at peace, and visit a plague of ugliness on the women of Afghanistan who are being mistreated and downtrodden by men in the name of Allah. But other alien races have also got plans for the verdant, overpopulated planet and they have chosen their own contact, a down and dirty government Senator. They don't want mankind to join the federation, though: they just want huinting rights on earth: hunting rights on man. The Fresco is Sheri Tepper at her very best, fast-paced, thought-provoking science fiction stuffed to the gills with strong characters, both good and bad, exotic aliens and mysterious new worlds.