But in America , a man who is not fit to run a business or a shop can tell the most powerful military machine on the planet what orders to follow...
It's true and the perfect example was Truman: President, Commander in Chief of the Armed Forces, unsuccessfull farmer and failed haberdasher.
Generals had problems with that too. From PBS's American Experience,
NARRATOR: Two weeks later, Truman prepared to leave America on a mission that caught everyone by surprise. "I've a whale of a job before me," Truman wrote his cousin, "Have to talk to God's right-hand man." Truman was heading for a tiny island in the middle of the Pacific to meet with General Douglas MacArthur. The General had been making trouble for the President. MacArthur's outspoken anti-communist opinions had inflamed an already tense situation with the Chinese. Many feared MacArthur wanted to re-take the communist Chinese mainland.
LUCIUS BATTLE: MacArthur had contempt for higher authority. He was the supreme authority. That's the way he saw himself. He was not troubled by the constitutional limits upon generals. He was not troubled by any obligations he had. I'm sure he had a certain contempt for the President. I don't think there's much doubt of that.
NARRATOR: Truman had never liked MacArthur. In his diary, the President described the General as "Mr. Prima Donna, Brass Hat," a "play actor and a bunco man." "It is a very great pity we have to have stuffed shirts like that in key positions," Truman wrote.
GENERAL EDWIN SIMMONS: The men were so dissimilar. Here was this imperious figure, very much different than the midwestern common man, who was Truman.
NARRATOR: As Truman headed for Wake Island and the meeting with his domineering General, he was determined to let MacArthur know who was boss. Truman put on his best public face, but tensions ran high from the moment the President got off the plane.
GENERAL VERNON WALTERS: And as I recollect it, MacArthur shook hands with the President. He did not salute him. Which struck me, as a young officer, right away, you know, sort of odd. Many years later, I was in Independence, Missouri, and I saw Mr. Truman. And I said, Mr. President, can I ask you an indiscreet question? He said, "Walters, there are no indiscreet questions, there are only indiscreet answers, and I'm a specialist in them. Go right ahead." I said, at Wake Island, when you emerged from the airplane and started down the stairs -- and he interrupted me and he said, "Did I notice that MacArthur did not salute? You're god damn right I noticed it. And I knew I was gonna have trouble with him."
NARRATOR: In a dilapidated Chevrolet, Truman and MacArthur set off for a private meeting. With them was Truman's secret service agent Floyd Boring.
FLOYD BORING, Secret Service: Oh, man, tension? I'll say there was tension. You could-- you could almost feel it, the tension in the air.
NARRATOR: Boring overheard the President lace right into the General.
FLOYD BORING: Never said "howdy" or nothin'. The President said to him, "I'm the Commander-in-Chief," and he was mad. "I'm the Commander-in-Chief. You're just -- you're a general in the Army. Remember that. Why do you insist on goin' into China. We don't want to do that." He said, "I want you to stop it. Otherwise, you're going to be recalled. We're going to get rid of you. General MacArthur didn't say anything. Yeah. He knew the old man was mad.