How do you respond to a disrespectful child?

Within reason, withhold kindness. Sometimes, it makes sense to do so because the kid is spoiled and is raised believing the more disrespectful they behave, the more others will bow and kiss their feet. Other times, it defeats the purpose because the child acts that way out of not ever knowing better because they actually never get much kindness. Being kind can cure some that haven't become cold or broken