The Republic of Vietnam (South Vietnam) had an open market economy mostly based on services, agriculture, and aid from the United States. Though formally a free market economy, economic development was based largely on five-year economic plans or four-year economic plans. Its economy stayed stable in the 10 first years, then it faced difficulties due to the escalation of the Vietnam War, which led to unsteady economic growth, high state budget deficits, high inflation, and trade deficits. The South Vietnamese government conducted land reforms twice. The United States played an important role in this economy through economic and technical aid, and trade.