"Warzone rape has been a taboo subject in all countries. You are helping to break down those taboos and redefining soldiering in the 21st century," Jolie said as the two addressed a conference on sexual violence in war organized in Sarajevo by Bosnia's Defense Ministry.
Hague said rape was a devastatingly effective way to terrorize and displace a population and is being used currently in Syria, the Central African Republic and South Sudan.
Jolie said the training was especially important for peacekeepers as their patrols "can mean that women no longer have to face a choice between going out for firewood and water and being raped or seeing their children go hungry."
Hague promised Britain will support a planned training center in Sarajevo for future military and police peacekeepers from the region.
Jolie and Hague launched a global campaign two years ago to fight sexual violence in armed conflicts, end impunity for the perpetrators and provide support for victims. So far, 141 countries have supported the initiative.
Up to 50,000 women were raped during the 1992-95 Bosnian war. The victims later sued at the UN war crimes tribunal, which resulted in wartime rapists being put behind bars for the first time in history.
Jolie and Hague later met widows and mothers of genocide victims in Srebrenica—a Bosnian town where Serb forces killed over 8,000 Muslim men and boys in 1995. Jolie came out of the meeting crying.