You have to change your kids diaper even if they hate that.
You have to put them in bed even if they do not understand that will be good for them.
You have to make them interact with other kids even if they are scared at first.
just because an adult (even a trusted adult) says so.
I am all in favor doing it gently and explaining and convincing them. This is why my use of force is in quotes. If stuff is less important (like phishing) I would only use convincing and maybe some easy punishment (if you stay at home you have to clean your room). But if something is really important (like changing a diaper) I will use physical force to do it.
However they do not have to do something just because adult said so. What adult says, should be backed by a good reason that is in kids best interest.