Partnered with the American firm of Victor Gruen Associates, Farmanfarmaian proposed his most important project, the Master plan of Tehran. This comprehensive plan, which was approved in 1968, identified the city problems to be high density, expansion of new suburbs, air and water pollution, inefficient infrastructure, unemployment, and rural-urban migration. To deal with these problems, the consortium envisioned a 25-year planning horizon which encouraged reducing the density and congestion of the city center through polycentric developments around Tehran. Eventually, the whole plan was 'marginalized' by the 1979 Iranian Revolution and the subsequent Iran–Iraq War.