Milan Martic appeared on the United Nations' International War Crimes Tribunal list for his actions as a rebel leader during The former Yugoslavia's ethnic war. Martic, a Serb, was a native of Krajina, a region of Croatia that became a battleground during the 1991 conflict between Croatia, Serbia, and Bosnia. Militia groups comprised of Croatia's Serbian minority began forming to take and hold areas like Krajina for the Serbian cause. In 1993, the Republic of Serbian Krajina was proclaimed, and later that year elections were held. Martic ran for president, but despite the powerful support he enjoyed from Serbian president Slobodan Milosevic, he lost to another nationalist, Milan Babic.

By the spring 1995, Croatia tried to retake Krajina. The Krajina Serbs, under Martic's command, retreated to their headquarters in the city of Knin, and Croatia began expelling Serbs from Krajina. In May of 1995, Martic okayed the deployment of cluster bombs on Zagreb, Croatia's capital. Orkan rockets released an estimated 3,000 cluster bombs into the middle of the city, some of which detonated near a hospital and a home for senior citizens. Seven people were killed and 150 wounded. In early 1996, the bombing was declared a criminal act by an international war crimes tribunal gathered at The Hague, Netherlands, and Martic fully accepted responsibility. He was absent at the hearing, however, having retreated to Banja Luka in northwest Bosnia. In the press, he defended the bombing, claiming it had been done to protect Serbs fleeing the Croatian army. He was not arrested for these actions.