The training for a life in a circus is for an elephant brutal and totally unacceptable from a welfare perspective from day 1. Most circus elephants have been taken from their mothers at a very young age, before going through a gruesome period of disciplining and basic training. Both during this period, and throughout the years of entertaining an ignorant audience, the training represents serious and continued abuse.
It is over and over again documented that active use of clubs and stabbing with bullhooks, pitchforks and electric prods is frequent in training sessions, with prolonged chaining and food and water deprivation used as "educational" punishment.
You may ask: Is it not possible to train an elephant for a life in a circus with positive reinforcement? Our answer is: No, it isn't. Circus people stating the opposite is lying, or defending their own inhumane practise. It is not possible to get an elephant to do highly unnatural and partly painful tricks exactly when you want it, day after day, without fear as a tool. And that fear of pain and abuse is what we are talking about.