The criteria we used were:

1 that the opera should have a general setting that would be adaptable to various situations and cultural contexts

2 that the opera includes children and adults.
Children aged 9-15 are on the whole well aware of social issues, and we feel confident that they can not only be able to tackle a difficult subject, but bring their own awareness to it

3 Since the emotions in such an opera are necessarily be intense, it is a shorter work, allowing concentration on singing and acting skills.

Consequently, the opera is quite stylized, in the sense that, say, a Weill work is stylized, as being the most appropriate to meet these criteria 

2 major child roles
2 minor child roles

children's chorus divided into two with solo lines for individuals

2 female adults, (soprano, mezzo-soprano), mothers, one doubling UN soldier
2 male adults, (tenor, baritone), fathers, one doubling UN soldier
UN officer
3-5 other adults, UN soldiers (non-singing)