A power vacuum is, in its broadest sense, an expression for a condition that exists when someone has lost control of something and no one has replaced them. It is usually used to refer to a political

Politics

Politics is a process by which groups of people make collective decisions. The term is generally applied to the art or science of running governmental or state affairs, including behavior within civil governments, but also applies to institutions, fields, and special interest groups such as the...

 situation that can occur when a government

Government

Government refers to the legislators, administrators, and arbitrators in the administrative bureaucracy who control a state at a given time, and to the system of government by which they are organized...

 has no identifiable central authority

Authority

The word Authority is derived mainly from the Latin word auctoritas, meaning invention, advice, opinion, influence, or command. In English, the word 'authority' can be used to mean power given by the state or by academic knowledge of an area .-Authority in Philosophy:In...

. The metaphor implies that, like a physical vacuum

Vacuum

In everyday usage, vacuum is a volume of space that is essentially empty of matter, such that its gaseous pressure is much less than atmospheric pressure. The word comes from the Latin term for "empty". A perfect vacuum would be one with no particles in it at all, which is impossible to achieve in...

, other forces will tend to "rush in" to fill the vacuum as soon as it is created, perhaps in the form of an armed militia

Militia

The term militia is commonly used today to refer to a military force composed of ordinary citizens to provide defense, emergency law enforcement, or paramilitary service, in times of emergency without being paid a regular salary or committed to a fixed term of service. It is a polyseme with...

 or insurgents

Iraqi insurgency

The Iraqi Resistance is composed of a diverse mix of militias, foreign fighters, all-Iraqi units or mixtures opposing the United States-led multinational force in Iraq and the post-2003 Iraqi government...

, military

Military

A military is an organization authorized by its greater society to use lethal force, usually including use of weapons, in defending its country by combating actual or perceived threats. The military may have additional functions of use to its greater society, such as advancing a political agenda e.g...

 coup

Coup d'état

A coup d'état state, literally: strike/blow of state)—also known as a coup, putsch, and overthrow—is the sudden, extrajudicial deposition of a government, usually by a small group of the existing state establishment—typically the military—to replace the deposed government with another body; either...

, warlord

Warlord

A warlord is a person with power who has both military and civil control over a subnational area due to armed forces loyal to the warlord and not to a central authority. The term can also mean one who espouses the ideal that war is necessary, and has the means and authority to engage in war...

 or dictator

Dictator

A dictator is a ruler who assumes sole and absolute power but without hereditary ascension such as an absolute monarch. When other states call the head of state of a particular state a dictator, that state is called a dictatorship...

.

Historian Fernand Braudel

Fernand Braudel

Fernand Braudel was a French historian and a leader of the Annales School. His scholarship focused on three main projects, each representing several decades of intense study: The Mediterranean , Civilization and Capitalism , and the unfinished Identity of France...

 compared the situation of Italy

History of Italy

Italy, united in 1861, has significantly contributed to the political, cultural and social development of the entire Mediterranean region. Many cultures and civilizations have existed there since prehistoric times....

 during the Renaissance

Renaissance

The Renaissance was a cultural movement that spanned roughly the 14th to the 17th century, beginning in Italy in the Late Middle Ages and later spreading to the rest of Europe. The term is also used more loosely to refer to the historical era, but since the changes of the Renaissance were not...

 as a "cyclonic zone, an enormous vacuum", which would sweep in foreign armies:

"The strength of the barriers in eastern and south-western Europe varied from century to century. The nomads' worlds rotated between these areas of negligence, weakness and sometimes ineffectual vigilance. A physical law drew them now westwards, now eastwards, according to whether their explosive life would ignite more easily in Europe, Islam, India or China. Eduard Fueter

Historiography of Switzerland

The historiography of Switzerland is the study of the history of Switzerland. Up until the late twentieth century, it was largely shaped by the centuries-old traditional account of the founding of the Old Swiss Confederacy through the Federal Charter of 1291 as a defensive alliance of small...

's classic work drew attention to a cyclonic zone, an enormous vacuum in 1494 over the fragmented Italy of princes and urban republics. All Europe was attracted towards this storm-creating area of low pressure. In the same way hurricanes persistently blew the people of the steppes eastwards or westwards according to the lines of least resistance.

During or following a civil war

Civil war

A civil war is a war between organized groups within the same nation state or republic, or, less commonly, between two countries created from a formerly-united nation state....

 there is often a power vacuum of some sort. For example, the war-torn

Somali Civil War

The Somali Civil War is an ongoing civil war taking place in Somalia. The conflict, which began in 1991, has caused destabilisation throughout the country, with the current phase of the conflict seeing the Somali government losing substantial control of the state to rebel forces...

 nation of Somalia

Somalia

Somalia , officially the Somali Republic and formerly known as the Somali Democratic Republic under Socialist rule, is a country located in the Horn of Africa. Since the outbreak of the Somali Civil War in 1991 there has been no central government control over most of the country's territory...

 is currently mired in a power vacuum, with no central government

Politics of Somalia

The politics of Somalia are defined by the state of civil war which, since 1991, has divided the country. What started out as various warring entities and autonomist and secessionist regions fighting for control developed into a fragile government fighting an Islamic insurgency. In 1991, Mohammed...

 or president exercising control over the supposed "Republic

Republic

A republic is a form of government in which the people, or some significant portion of them, have supreme control over the government and where offices of state are elected or chosen by elected people. In modern times, a common simplified definition of a republic is a government where the head of...

 of Somalia".

The start of civil war in Bosnia in 1992 was marked with a power vacuum following disintegration of Yugoslavia.

A power vacuum can also occur following a constitutional crisis

Constitutional crisis

A constitutional crisis is a situation that the legal system's constitution or other basic principles of operation appear unable to resolve; it often results in a breakdown in the orderly operation of government...

 in which large portions of the government resign or are removed, creating unclear issues regarding succession

Order of succession

An order of succession is a formula or algorithm that determines who inherits an office upon the death, resignation, or removal of its current occupant.-Monarchies and nobility:...

 to positions of power.

After the Second World War

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, there was a power vacuum in Europe. Along with the division of East

German Democratic Republic

The German Democratic Republic , informally called East Germany by West Germany and other countries, was a socialist state established in 1949 in the Soviet zone of occupied Germany, including East Berlin of the Allied-occupied capital city...

 and West Germany

West Germany

West Germany is the common English, but not official, name for the Federal Republic of Germany or FRG in the period between its creation in May 1949 to German reunification on 3 October 1990....

, Stalin

Joseph Stalin

Joseph Vissarionovich Stalin was the Premier of the Soviet Union from 6 May 1941 to 5 March 1953. He was among the Bolshevik revolutionaries who brought about the October Revolution and had held the position of first General Secretary of the Communist Party of the Soviet Union's Central Committee...

's diplomacy

Foreign relations of the Soviet Union

At its founding, the Soviet Union was considered a pariah by most governments because of its communism, and as such was denied diplomatic recognition by most states...

 and governance

Stalinism

Stalinism refers to the ideology that Joseph Stalin conceived and implemented in the Soviet Union, and is generally considered a branch of Marxist–Leninist ideology but considered by some historians to be a significant deviation from this philosophy...

, the development

History of nuclear weapons

The history of nuclear weapons chronicles the development of nuclear weapons. Nuclear weapons possess enormous destructive potential derived from nuclear fission or nuclear fusion reactions...

 of the atomic bomb

Nuclear weapon

A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion. Both reactions release vast quantities of energy from relatively small amounts of matter. The first fission bomb test released the same amount...

, policies

Foreign policy

A country's foreign policy, also called the foreign relations policy, consists of self-interest strategies chosen by the state to safeguard its national interests and to achieve its goals within international relations milieu. The approaches are strategically employed to interact with other countries...

 of containment

Containment

Containment was a United States policy using military, economic, and diplomatic strategies to stall the spread of communism, enhance America’s security and influence abroad, and prevent a "domino effect". A component of the Cold War, this policy was a response to a series of moves by the Soviet...

 of communism

Communism

Communism is a social, political and economic ideology that aims at the establishment of a classless, moneyless, revolutionary and stateless socialist society structured upon common ownership of the means of production...

, the expansionism of the USSR

Soviet Union

The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

 and USA and a growing lack of trust (fear of a hegemony

Hegemony

Hegemony is an indirect form of imperial dominance in which the hegemon rules sub-ordinate states by the implied means of power rather than direct military force. In Ancient Greece , hegemony denoted the politico–military dominance of a city-state over other city-states...

) were seen to be factors in the emergence of the Cold War

Cold War

The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...

.

More recently, the tight control which Saddam Hussein

Saddam Hussein

Saddam Hussein Abd al-Majid al-Tikriti was the fifth President of Iraq, serving in this capacity from 16 July 1979 until 9 April 2003...

's Baath party exerted on Iraq

Iraq

Iraq ; officially the Republic of Iraq is a country in Western Asia spanning most of the northwestern end of the Zagros mountain range, the eastern part of the Syrian Desert and the northern part of the Arabian Desert....

 could have been exploited during a transitional hand-over period following the 2003 invasion of Iraq

2003 invasion of Iraq

The 2003 invasion of Iraq , was the start of the conflict known as the Iraq War, or Operation Iraqi Freedom, in which a combined force of troops from the United States, the United Kingdom, Australia and Poland invaded Iraq and toppled the regime of Saddam Hussein in 21 days of major combat operations...

. Instead, the US Government's policy of purging Baath party members from the Iraqi government after the invasion created a power vacuum which was quickly filled by insurgents

Iraqi insurgency

The Iraqi Resistance is composed of a diverse mix of militias, foreign fighters, all-Iraqi units or mixtures opposing the United States-led multinational force in Iraq and the post-2003 Iraqi government...

, who then began to attack American service personnel using improvised explosive devices and snipers.

The general concept of a "power vacuum" is relevant to many personal and organizational situations. In the criminal world many drug lords are able to become untouchable because of fear of any backlash occurring in a power vacuum situation.