Its not just a US thing, other places in the world have fluoride in their water. In many areas fluoride just naturally occurs in the water at levels even higher than what managed services target. But other countries, such as Hong Kong, parts of Malaysia, Singapore, Ireland, parts of Spain, parts of the UK, parts of Canada, Mexico fluoridates table salt, most of Austrailia, Fiji is rolling out a program, half of New Zealand, about half of Brazil, and most of Chile all have some water fluoridation programs. Many other countries did at some other point in time but stopped doing it.

Fluorinated water has its own health risks, but everyone should absolutely be using either a fluoride toothpaste or fluoride rinse.