I think that Truman's dismissal of Macarthur stood as an example of how the military must remain under control of the President.  The role of Commander- in - chief was something that Truman demonstrated in his dismissal of Macarthur.  The practice of ensuring that the military cannot go against the orders of the President was reaffirmed when Truman dismissed the popular general of his field duties.  Truman recognized the need for the President during war to be in control of the military and what is done in the name of the United States Armed Forces.  Macarthur's disagreement with the President and then going to members of Congress in order to voice his discontent and advocate his agenda was counter to that of the President.  Truman established a precedent in that the military must be under the control of the President.  Since that point, even military endeavors that have been widely unpopular, have featured military leaders that have followed the will of the President and not openly disobeyed them.  Truman's dismissal of Macarthur helped to enshrine that precdent, demonstrating that the military is always under civilian control.