What is the main conflict in Persian Letters. Translated with an Introd. and Notes, by C. J. Betts by Charles de Montesquieu?

Usbek is the central character in The Persian Letters. He is a Muslim from Ispahan, Persia. Usbek has at least five wives who live in concealment at a seraglio. Usbek travels out of Persia into the European countries under the guise of seeking knowledge. In reality, Usbek is exiled from Persia because he discovers some sort of failing in the government of Persia. When he alerts others to this failing, however, he finds he has made many enemies. Usbek leaves his home country because he is in fear of losing his life. Only his friend Rustan knows the real reason that Usbek left Persia.