However, once again, trouble arose. The Polish protests and Hungarian uprising led to major social and economic changes, including the 1957 abandonment of the 1956–60 Soviet five-year plan, as the Comecon governments struggled to reestablish their legitimacy and popular support. The next few years saw a series of small steps toward increased trade and economic integration, including the introduction of the "", revised efforts at national specialization, and a 1959 charter modeled after the 1957 Treaty of Rome.