Military discipline and effectiveness is built on the foundation of obedience to orders. Recruits are taught to obey, immediately and without question, orders from their superiors, right from day-one of boot camp.
Military members who fail to obey the lawful orders of their superiors risk serious consequences. Article 90 of the Uniform Code of Military Justice (UCMJ) makes it a crime for a military member to WILLFULLY disobey a superior commissioned officer. Under Article 90, during times of war, a military member who willfully disobeys a superior commissioned officer can be sentenced to death. Article 91 makes it a crime to WILLFULLY disobey a superior Noncommissioned or Warrant Officer. Article 92 makes it a crime to disobey any lawful order (the disobedience does not have to be "willful" under this article). These articles require the obedience of LAWFUL orders. An order which is unlawful should not be obeyed; obeying such an order can result in criminal prosecution of the one who obeys it.
“We follow orders or people die” by Col. Jessep portrayed by Jack Nicholson in the movie A Few Good Men.
This quote is true because disobeying orders can cost people there lives, more people than just the one disobeying those orders. In a time of war orders can go from shoot on sight to hold your fire even if fired upon