It would probably be difficult to staff the diplomatic corps with childless people only. Among other things, I don't know how moral or legal it would be to ask

It would probably be difficult to staff the diplomatic corps with childless people only. Among other things, I don't know how moral or legal it would be to ask people to remain childless or face the end of your career. Having met maybe a dozen or so people in your situation, my general impression is that they share your concern, but not necessarily to the degree where they would consider it to outweigh the benefits of growing up under these circumstances. Letting diplomats remain at the same post for longer would seem to be a possible improvement. Unfortunately, there is a purpose behind all that moving around, namely avoiding networks of corruption to form and/or practices diverging. It'd be interesting to hear about the experience of children of military families. The problems are similar, but the benefits not: a diplomat's children get to life in the capital, usually attend the best schools, and enjoy all the variety of cultural happenings and high social status. For children on a military base, being mostly around others with the same background might be slightly more comfortable. But beyond that, I would imagine the environment to be drab and isolating.