The leaders of Bosnia and Herzegovina, Serbia, Croatia and Montenegro work together to resolve the issue of missing persons.
Joint work and co-operation are seen as the best tools to accelerate the EU accession process.
Participants in foreign conflicts can receive jail sentences of at least five years.
The proposed law, which would be supported by a loan from the World Bank, is being considered by Parliament. In other business news: optimism grows for the economy's future in southeast Europe.
Regional officials say the recent personnel changes in the EU will have a positive impact on their countries' relationship with Brussels.
EU-funded exchange programmes help Balkan students and teachers to learn from European experiences, raising the level of education in the region.