The Assistant to the President for National Security Affairs, commonly referred to as the National Security Advisor (abbreviated NSA, or sometimes APNSA or ANSA to avoid confusion with the abbreviation of the National Security Agency), is a senior official in the Executive Office of the President who serves as the chief advisor, stationed in the White House, to the President of the United States on national security issues. This person also participates in the meetings of the National Security Council. The National Security Advisor's office is located in the West Wing of the White House. He or she is supported by the National Security Council staff that produces research, briefings, and intelligence for the APNSA to review and present either to the National Security Council or directly to the President.

The current Assistant to the President for National Security Affairs is Thomas E. Donilon.

The Assistant to the President for National Security Affairs is appointed by the President without confirmation by the United States Senate. However, the APNSA is a staff position in the Executive Office of the President and does not have line authority over either the Department of State or the Department of Defense, but is able, as a consequence thereof, to offer advice to the President - unlike the Secretary of State and the Secretary of Defense who are senate-confirmed officials with line authority over their departments - independently of the vested interests of the large bureaucracies and clientele of those departments. The influence and role of the National Security Advisor varies from administration to administration and depends heavily on the qualities of the person appointed to the position.

National security is the requirement to maintain the survival of the state through the use of economic, diplomacy, power projection and political power. The concept developed mostly in the United States of America after World War II. Initially focusing on military might, it now encompasses a broad range of facets, all of which impinge on the non military or economic security of the nation and the values espoused by the national society. Accordingly, in order to possess national security, a nation needs to possess economic security, energy security, environmental security, etc. Security threats involve not only conventional foes such as other nation-states but also non-state actors such as violent non-state actors, narcotic cartels, multinational corporations and non-governmental organisations; some authorities include natural disasters and events causing severe environmental damage in this category.

Measures taken to ensure national security include:

There is no single universally accepted definition of "National Security" since there are some differences on describing National as State and everything consist in a nation. The variety of definitions provide an overview of the many usages of this concept. The concept still remains ambiguous, having originated from simpler definitions which initially emphasised the freedom from military threat and political coercion to later increase in sophistication and include other forms of non-military security as suited the circumstances of the time.

Susan Elizabeth Rice (born November 17, 1964) is an American diplomat, former think tank fellow, and civil servant. She is an American foreign policy advisor and United States Ambassador to the United Nations. Rice served on the staff of the National Security Council and as Assistant Secretary of State for African Affairs during President Bill Clinton's second term. Rice was confirmed as UN Ambassador by the U.S. Senate by unanimous consent on January 22, 2009.

Rice was born in Washington, D.C. Her father, Emmett J. Rice (1919–2011), was a Cornell University economics professor and governor of the Federal Reserve System. Her mother is education policy scholar Lois Dickson Fitt, currently at the Brookings Institution. Her brother, John Rice, received an M.B.A. from Harvard Business School and is the founder of Management Leadership for Tomorrow (an organization committed to developing top minority talent for leadership roles in the business and non-profit sector). She is not related to Condoleezza Rice.

Samuel Richard "Sandy" Berger (born October 28, 1945) was United States National Security Advisor, under President Bill Clinton from 1997 to 2001. In his position, he helped to formulate the foreign policy of the Clinton Administration. During this time he advised the President regarding the Khobar Towers bombing, Operation Desert Fox, the NATO bombing campaign against Yugoslavia, responses to the terrorist bombings of American embassies in Kenya and Tanzania, and the administration's policy of engagement with the People's Republic of China. He was also one of the prominent actors of the Camp David 2000 Summit.

Before joining the administration, Berger had worked as an international trade attorney; currently, he is chairman of an international advisory firm and chairman of the board of an international investment fund. He lives in the Georgetown section of Washington, D.C., is married to Susan Berger and has three children (one son and two daughters).

In April 2005, Berger pled guilty to a misdemeanor charge of unauthorized removal and retention of classified material from the National Archives in Washington. According to the lead prosecutor in the case Berger only took copies of classified information and no original material was destroyed.

Vladimir Vladimirovich Putin (Russian: Влади́мир Влади́мирович Пу́тин; IPA: [vɫɐˈdʲimʲɪr vɫɐˈdʲimʲɪrəvʲɪtɕ ˈputʲɪn] ( listen); born 7 October 1952) is a Russian politician who has been the President of Russia since 7 May 2012. Putin previously served as President from 2000 to 2008 and as Prime Minister of Russia from 1999 to 2000, and again from 2008 to 2012. Putin also serves as chairman of United Russia and Chairman of the Council of Ministers of the Union of Russia and Belarus. He became acting President on 31 December 1999, when president Boris Yeltsin resigned in a surprising move. Putin won the 2000 presidential election; in 2004 he was re-elected for a second term lasting until 7 May 2008.

Because of constitutionally mandated term limits, Putin was ineligible to run for a third consecutive presidential term. After his successor Dmitry Medvedev won the 2008 presidential election, Putin was nominated by Medvedev to be Russia's Prime Minister; Putin took office on 8 May 2008 and a period of so-called "tandemocracy" followed. In September 2011, Putin and Medvedev agreed he should seek a third, non-consecutive term in the 2012 presidential election, which he won in the first round on 4 March 2012.