tall-p wrote:
Citizens get to choose whether or not to get their children inoculated but anyone coming in must have them?
If you live in the USA, the risk of EXPOSURE to those diseases are known. If you are from outside the USA, the risk of exposure is an unknown and vaccinations may be required for entry.
Otherwise, one carrier coming into the USA could expose thousands of people (vaccinate or not...it doesn't guarantee you can't get the disease) to something that isn't naturally occurring within the domestic population.
Same reason you'd want to make sure your vaccinations are up-to-date if you are leaving the USA and going someplace with lesser sanitation/disease control than what you are used to.