SDI research was cut back following the end of Reagan's presidency, and in 1995 it was reiterated in a presidential joint statement that " missile defense systems may be deployed ... will not pose a realistic threat to the strategic nuclear force of the other side and will not be tested to ... that capability.

After that the National Space-Based Positioning, Navigation and Timing Executive Committee was established by presidential directive in 2004 to advise and coordinate federal departments and agencies on matters concerning the GPS and related systems.

In parliamentary systems, the word " government " is used to refer to what in presidential systems would be the executive branch and to the governing party.

In presidential systems, the term refers to a regularly-scheduled election where both the president, and either " a class " of or all members of the national legislature are elected at the same time.

The older the constitution, the more constitutional leeway tends to exist for a head of state to exercise greater powers over government, as many older parliamentary system constitutions in fact give heads of state powers and functions akin to presidential or semi-presidential systems, in some cases without containing reference to modern democratic principles of accountability to parliament or even to modern governmental offices.

Semi-presidential systems combine features of presidential and parliamentary systems, notably a requirement that the government be answerable to both the president and the legislature.

It is notable that some presidential systems, while not providing for collective executive accountability to the legislature, may require legislative approval for individuals prior to their assumption of cabinet office and empower the legislature to remove a president from office ( for example, in the United States of America ).

Most presidents in such countries are selected by democratic means ( popular direct or indirect election ); however, like all other systems, the presidential model also encompasses people who become head of state by other means, notably through military dictatorship or coup d ' état, as often seen in Latin American, Middle Eastern and other presidential regimes.

In a sense, elected monarchies, such as the Holy See, the defunct Holy Roman Empire or pre 16th century Swedish monarchy, can be regarded as ' crowned ' presidential systems.

In presidential systems, such as that of the United States, appointments are nominated by the President's sole discretion, but this nomination is often subject to parliamentary confirmation ( in the case of the US, the Senate has to approve cabinet nominees and judicial appointments by simple majority ).

In presidential systems, the president often has the power to fire ministers at his sole discretion.

Even in presidential systems the head of state often formally reports to the legislature on the present national status, e. g. the State of the Union address in the United States of America.

In some parliamentary systems, and in some presidential systems, however, the head of state may do so on their own initiative.

Typically in presidential and semi-presidential systems the president is directly elected by the people, or is indirectly elected as done in the United States.

For example, it is used in French presidential, legislative, and cantonal elections, and also to elect the presidents of Afghanistan, Argentina, Austria, Brazil, Bulgaria, Chile, Colombia, Costa Rica, Croatia, Cyprus, Dominican Republic, Ecuador, Egypt, Finland, France, Ghana, Guatemala, India, Indonesia, Liberia, Peru, Poland, Portugal, Romania, Senegal, Serbia, Slovakia, Slovenia, Timor-Leste, Ukraine, Uruguay, Zimbabwe — see: Table of voting systems by nation.

In democratic systems of governance based on the trias politica, a fundamental parallel and a fundamental difference exists between presidential systems and constitutional monarchic parliamentary system of government.

* In presidential systems, the incumbent of the Head-of-state is elected to office and, after transfer of power, appoints his administration ( like in the United States, with unitary executive ) or a government headed by a prime minister is formed within the parliament, based on the elected majority ( like in France ).

Complete separation-of-powers systems are almost always presidential, although theoretically this need not be the case.

Countries with Congresses and presidential systems:

Since the adoption of a new constitution, early in 2010, the politics of Angola takes place in a framework of a presidential republic, whereby the President of Angola is both head of state and head of government, and of a multi-party system.

Politics of Armenia takes place in a framework of a presidential representative democratic republic, whereby the President is the head of government, and of a platform multi-party system.

Politics of American Samoa takes place in a framework of a presidential representative democratic dependency, whereby the Governor is the head of government, and of a pluriform multi-party system.

The government operates under a framework of a presidential representative democratic dependency, whereby the Governor of American Samoa is the head of government.

* 1925 – Paul von Hindenburg defeats Wilhelm Marx in the second round of the German presidential election to become the first directly elected head of state of the Weimar Republic.

The politics of Brazil take place in a framework of a federal presidential representative democratic republic, whereby the President is both head of state and head of government, and of a multi-party system.

The Politics of Burkina Faso takes place in a framework of a presidential republic, whereby the President of Burkina Faso is both head of state and head of government, and of a multi-party system.

Politics of Burundi takes place in a framework of a transitional presidential representative democratic republic, whereby the President of Burundi is both head of state and head of government, and of a multi-party system.

Politics of Chad takes place in a framework of a presidential republic, whereby the President of Chad is both head of state and head of government.

The politics of Cameroon takes place in a framework of a unitary presidential republic, whereby the President of Cameroon is both head of state and head of government, and of a multi-party system.

Politics of the Central African Republic takes place in a framework of a presidential republic, whereby the President is both head of state and head of government, with a separate executive Prime Minister.

The politics of Chile takes place in a framework of a presidential representative democratic republic, whereby the President of Chile is both head of state and head of government, and of a formal multi-party system that in practice behaves like a two-party one, due to binomialism.

The government of Ivory Coast takes place in a framework of a presidential representative democratic republic, whereby the President of Ivory Coast is both head of state and head of government, and of a multi-party system.

Politics of the Republic of Cyprus takes place in a framework of a presidential representative democratic republic, whereby the President of Cyprus is both head of state and head of government, and of a multi-party system.

The Politics of Colombia take place in a framework of a presidential representative democratic republic, whereby the President of Colombia is both head of state and head of government, and of a multi-party system.

And in this country Gustave Weigel's delineation of the line between the sacral and secular orders during the last presidential campaign served to provide a most impressive Roman Catholic defense of the practical autonomy of both church and state.

An exceptionally astute politician deeply involved with power issues in each state, he reached out to War Democrats and managed his own re-election in the 1864 presidential election.

In 1840 Johnson was appointed as a presidential elector for his state, giving him more statewide exposure.

Politics of the Union of the Comoros takes place in a framework of a federal presidential republic, whereby the President of the Comoros is both head of state and head of government, and of a multi-party system.

Politics of Ecuador takes place in a framework of a presidential representative democratic republic, whereby the President of Ecuador is both head of state and head of government, and of a multi-party system.

Politics of El Salvador takes place in a framework of a presidential representative democratic republic, whereby the President of El Salvador is both head of state and head of government, and of a multi-party system.

Politics of Equatorial Guinea takes place in a framework of a presidential republic, whereby the President is both the head of state and head of government.

Politics of Eritrea takes place in a framework of a single-party presidential republic, whereby the Eritrean President is both head of state and head of government and a single-party state, led by the People's Front for Democracy and Justice.

In a presidential system the leader of the executive branch is at once the head of state and head of government.

The Politics of Georgia is based on a presidential representative democratic republic ( semi-presidential system ), with a multi-party system, and the President as the head of state and the Prime Minister as the head of the Georgian Government.

The 1975 constitution, which describes Greece as a " presidential parliamentary republic ", includes extensive specific guarantees of civil liberties and vests the powers of the head of state in a president elected by parliament.

Politics of Guatemala takes place in a framework of a presidential representative democratic republic, whereby the President of Guatemala is both head of state and head of government, and of a multi-party system.