Officially the Hashemite Kingdom of Jordan, and lying east of the Jordan River, the vast majority of the population is Arab, with a large number of Palestinians who fled during the Arab-Israeli wars. As a constitutional monarchy with a mixed economy, Jordan is classified as an upper-middle income country. However, political struggles have flared over the years, especially with relation to the PLO and with Israel. Some current development challenges include startling high unemployment rates, difficulty integrating large numbers of refugees from Syria, and severe water strain.