Peace is defined as a state of tranquility and calmness and when it is used in political sense, it means either an end of hostilities between two antagonistic countries, or a period of prosperity and agreement between two or more countries, nations or groups. Peace is often seen as the opposite of war and some people believe that with the permanent absence of war, the world can exist in a state of constant freedom, happiness and concord. Others argue that war and violence are an integral part of human nature and there are people who choose to act violently. Another theory states that world peace cannot be achieved because war is the natural way to deal with overpopulation and the overuse of natural resources.
Rarely, if at all, have there been calm periods of world peace. In most historical periods there have been wars going on in various parts of the globe. Theories of peace have, therefore, been attractive for governments, people in positions of power and for ordinary people and numerous approaches and methods of achieving universal peace have been developed. One of the most radical views on peace was the Marxist concept of permanent revolution, further developed by Soviet revolutionary, politician and founder of the Red Army, Leon Trotsky (1879-1940). He believed that by permanent revolution against capitalism and by eliminating the bourgeoisie, substituting proletariat (working class) instead in numerous countries, this would eventually lead to an entirely communist world and thus, global peace could be achieved.
Contrary to Trotsky's theory, the Democracy Peace Theory states that peace is inherent to democracy. It claims that democratic nations are generally more peaceful in their foreign policy and never fight each other because they can resort to democratic values to resolve possible conflicts. According to this theory, the only way to achieve world peace is through democracy and overthrowing all other regimes and political systems. The theory stems from Kantian philosophy and was very popular at the end of the 20th century. Many world leaders are proponents of this theory. Former President George W. Bush said in his 2004 State of the Union Address: "Our aim is a democratic peace - a peace founded upon the dignity and rights of every man and woman."
Among the most prominent pacifists was civil rights activist Martin Luther King Jr (1929-1968), who was a strong critic of war - and more specifically - the Vietnam War (1954-1975). He claimed that the US government was involved in the conflict because it was trying to colonize Vietnam, not to free it from Vietcong. King also argued that the war was taking far too much money and resources which could in fact be directed to social welfare. During the 1960s, which was the height of the civil rights campaign, the hippie movement focused on world peace and harmony. The term "hippie" was coined by San Francisco writer Michael Fallon in 1965 in an article entitled A New Haven for Beatniks.
A number of international pacifist organizations promote peace around the world. The largest of them, Greenpeace, with offices in over 40 countries, combines purely political pacifism, such as the problem of nuclear energy use in relation to issues on environment conservation. Officially, the main role of a global peacekeeper has been taken up by the United Nations (UN). More than 120,000 people occupy positions connected to UN peacekeeping missions and all UN Member States are invited to contribute troops. The majority of UN "blue helmets" come from South Asia and Africa. In 2010, the top five troop contributing countries were Bangladesh, Pakistan, India, Nigeria and Egypt. UN peacekeepers have been deployed in countries where there is either civil war or international conflicts. They have played a significant role in Middle East and Balkan conflicts and in African civil wars. In 2011, there were 16 UN peacekeeping missions in action.
Most of the world's religions are markedly pacifist and promote notions such as love and forgiveness. For example, Judaism predicts that the Messiah will bring everlasting peace and prosperity, while Buddhists believe that peace comes from within and world peace will reign when all people clear their minds of evil thoughts and intentions. In Christianity, peace, love and forgiveness are the basic principles and faithful Christians are expected to do no harm. One of the most famous sayings in Hinduism translates as "The World is One Family." The word Islam derives from the Arab word salaam, which means peace.