If a person or people violate the Geneva Conventions they are liable to be tried for war crimes. However, there is no permanent or objective body that has been created to enforce the conventions or to prosecute war crimes.
In order for someone to be tried for a war crime, his side generally has to lose the war. This is what happened in World War II. The Axis lost the war and so the Aliies set up tribunals to prosecute war crimes.
Recently, there have been special tribunals set up through the UN to prosecute alleged war crimes that ocurred in the former Yugoslavia and in Rwanda.
Geneva convention refers to international agreement among most of the nations of the world providing for human treatment o civilians, prisoners and wounded persons in war time. These agreement have been reached over a long period starting nineteenth century. These agreements, with some reservations have been ratified by nearly 200 nations.
The first such agreement was reached in 1864. This agreement also provided for establishment of the Red Cross.This original convention was accepted by all European countries, the USA, and a few other countries in Asia and South America. Additions and amendments to Geneva conventions were made in 1906, 1929, 1949, 1977and 2005.
Geneva convention includes provision for conduct of countries in matters such as treatment and and care of the military personnel wounded in the field, and those shipwrecked members of armed forces at sea. The convention also provides for protection of civilians and members armed forces, and volunteer forces. It specifies methods to identify the dead and wounded, and to send information to their families. It also provides for identification and protection of medical transports.
In conferences held at The Hague in 1899 and 1907, the laws of war, of peace, and of neutrality were collected and embodied in 14 conventions of Geneva convention, covering subjects as the rights and duties of neutral countries, and the peaceful settlement of international disputes.