Although Salinas won by fraud, he embarked on a program of neoliberal reforms which fixed the exchange rate of the peso, controlled inflation, opened Mexico to foreign investment, and began talks with the U.S. and Canada to join their free-trade agreement. In order to do that, the Constitution of 1917 was amended in several important ways. Article 27, which allowed the government to expropriate natural resources and distribute land, was amended to end agrarian reform and to guarantee private owners' property rights.  The anti-clerical articles that muzzled religious institutions, especially the Catholic Church, were amended and Mexico reestablished of diplomatic relations with the Holy See, to which the Mexican State did not recognize as a political entity. Signing on to the North American Free Trade Agreement (NAFTA) removed Mexico's autonomy over trade policy. The agreement came into effect on 1 January 1994; the same day, the Zapatista Army of National Liberation (EZLN) started a two-week-long armed rebellion against the federal government, and has continued as a non-violent opposition movement against neoliberalism and globalization.