Spoken to me, at 11 years of age, I had no idea of its military origin, but understood the terrible meaning. Behave, or end up somewhere else much worse. The second part of the threat solidified that idea. “Or we’ll move away and leave you behind.”
* It is a phrase of World War II in America when armed forces first used this command. It suggested that the sailors, soldiers or marines are warned to adapt according to the rules and regulations or rightfully perform their tasks they are supposed to, if they are to stay in the field otherwise they would be expelled or sent to back zone. Later the phrase was expanded to include all areas in which improvement and performances were demanded.