I’ll just throw my hat in the “one state solution” camp. In the case of Israel/Palestine at least, I don’t think that is possible anymore without first dissolving the current state of Israel. But maybe there is an alternate history somewhere, where the early Jewish settlers who arrived in the region cooperated with the native Palestinians to form a secular state promising freedom of religion for all, avoiding most of these long-term issues.

Carving out countries on religious/ethnic boundaries (to this extent, at least) fosters more division and resentment than anything else.