Before Mattis, the one exception to the law had been made for General of the Army George C. Marshall, the chief of staff of the United States Army during World War II, and one of the architects of victory. That change, in September 1950, was made under the pressure of emergency: The war in Korea, which had begun in June of that year, had gone badly for its first months while the United States was rushing divisions to Europe to guard against a feared Soviet attack there. The Soviets had set off an atom bomb only a year before, shocking a complacent America. The first secretary of defense, Louis Johnson, was palpably incompetent and had been fired. President Harry Truman believed that the American people needed the reassurance and the massive competence that Marshall could bring, and with congressional consent, the appointment was made.
In 2017, the situation was different, but in its own way dire. I testified:
I have sharply criticized President [Barack] Obama’s policies, but my concerns pale in comparison with the sense of alarm I feel about the judgment and dispositions of the incoming White House team. In such a setting, there is no question in my mind that a Secretary Mattis would be a stabilizing and moderating force, preventing wildly stupid, dangerous, or illegal things from happening, and over time, helping to steer American foreign and security policy in a sound and sensible direction.
Marshall did indeed reassure the American people, and Mattis did indeed block, or at least slow down, some of the wild fancies of Donald Trump.
But the exceptions prove the rule. The arguments against putting a general in as secretary of defense remain overpoweringly correct: The legislation requiring a minimum of seven years’ separation (10 would be better) is sound. The Department of Defense is the biggest element in the United States government. It has immense resources of people, money, and machines, and overpowering amounts of violence at its disposal. It is a vital principle of free government that such power not be put in the hands of members of a military elite, no matter how honorable and trustworthy they may be as individuals.
For secretary of defense, Americans should want someone of broad experience and perspective in civilian life, not the product of an all-absorbing institution as total in its way as the priesthood in the Catholic Church. The military way is a noble way. It is also a narrow way. There are practical issues as well: Would a soldier favor his own service in intramural budget battles, or bend over backwards not to? Would he concentrate on policy rather than the kind of tactical management generals feel most comfortable with?
The biggest argument is more fundamental. The secretary of defense represents the armed forces to society at large, and far more important, represents society to the armed forces. Selecting a civilian ensures that civilian perspectives dominate, as they should.