In all presidential systems the president and a majority in the legislature must both support a policy for it to become law, though different systems differ in the specific division of powers between the two branches. Who initiates policy changes or budgets, who can veto or preempt legislation and how who can declare war or approve foreign policy decisions in general these details vary from country to country. Nonetheless, in all presidential systems the crucial concept of separation of powers has potentially positive and negative aspects. These became a source of hot debate in the 1990s, as formerly communist or authoritarian countries in Eastern Europe, Latin America, and Africa considered what kind of institutional arrangements would best serve their nascent democracies. Supporters of presidentialism saw many advantages. The Founders of the United States believed that the separation of powers would provide checks and balances that would diminish the concentration of power and the potential for its abuse in any one part of the government. Without a doubt the separation of powers makes the development of policies an iterative process with give and take among the branches by slowing down the legislative process, a form of horizontal accountability. There is also some advantage to having a head of state and government biose direct election provides democratic legitimacy that can be seen as reflect- ing the national will. Whatever divisions exist in the legislature, the executive can arguably act as a unifying force for the country Fixed terms can also be an advan- tage since they provide a timeline for the development of policy and accomplish- ment of objectives that allows legislators and the executive to think in the long term rather than worrying the government will fall imminently providing greater predictability and stability.