A power vacuum can quickly become a dangerous situation. It is a political term used to describe a vacancy or weakness in the power structure of a nation or region. The danger is that a group that does not have the country or region’s best interests in mind may fill the vacuum before an appropriate new government can be installed. This is whatsome fear will occur if the U.S. and Coalition forces leave Iraq too soon, allowing the not yet firmly established government to be taken over by those who have more concern for their own interests than they do for the Iraqi people.
Iraq is a good example of a power vacuum, because it is what occurs when a long time dictator is ousted or displaced for whatever reason. This type of situation may also occur after a civil war or other insurrection where various factions rise up to demand more control over their own governance. Other causes include coup d`etat which in effect is comparable to the latter. A vacuum may also occur, and is very likely, following a constitutional crisis.
A civil war may leave a country without leadership or with a weakened government, allowing the most powerful of the fighting forces to take over. A coup generally occurs when one faction uses military means to directly overthrow a government at its highest levels. Those using force then fill the power vacuum with their own choice of leaders, which are often military leaders.
More formally, a coup would restructure the entire government rather than simply effecting a regime change. While a modern coup often still includes some form military force, or the threat thereof, it will frequently install civilian leadership to fill the power vacuum or replace the regime, instead of installing members of the military.
In the event of a constitutional crisis, a power vacuum is frequently created because a staggering number of government officials decide to step down at once, for whatever reason. This is sometimes described as a non-violent revolution, and it usually ends up leaving the government in chaos. There is little if any leadership and the sudden exodus incites many questions and arguments regarding succession. This is another reason a power vacuum may leave a government incredibly vulnerable, since in this case it may seriously hamper the ability to fill various leadership positions.