Read a science fiction story in 60s-70s. Involved a planet colonized by humans brought there as embryos and raised by robots. They loose contact with earth that is militarized and sends US ship ship and China ship to recontact the lost colony and bring them into the fold.
Colonists have society without money where people do what they enjoy, and leadership is something earned by respect of others due to performance. The colonists co-opt the crew by offering a better way to life.
When military leaders on ship decide to take colony by force it is discovered the colonists have a super weapon that could easily destroy ship. They had tested on their moon before ship arrived blasting a large crater.
Does anyone recall this story, title author, possible reprint? Thanks