I am reading portions of Makers of Modern Strategy: from Machiavelli to the Nuclear Age and the first truly striking observation I have is that modern American society's conception of a "professional soldier" differs greatly from the historical definition. From personal experience, I would guess that the average American thinks of "professional soldier" as synonymous with "mercenary". The truth is exactly the opposite. The military revolution of the 16th and 17th centuries was a movement away from mercenaries, who were considered ill-disciplined because of their propensity to "mutiny, desert, or defect, paralyzing operations." In place of mercenaries, governments began to focus on first militias and then standing armies of their own citizens. The pivotal ideas behind this shift were "the need for discipline and the notion that society had a military obligation."
Resolving the problem, the Orangist reformers created a new type of professional soldier and combat leader, combining marital expertise with specific social and spiritual values.
This new "professional soldier" stood in direct contrast to their mercenary contemporaries. I would argue that the distinction is once again clear based on the conduct of America's wars in Afghanistan and Iraq. The key that distinguished the professional soldier from the mercenary was not military expertise --- which both possessed --- but discipline and a responsibility to society, encoded in a set of virtues and values.
As an outside observer (from a conventional background), the US military's recent issues with SOF (not to mention actual mercenaries) feel like an outgrowth of a military culture that worships tactical prowess, without remorse. I think it would be better to have professional soldiers whose highest responsibility is to society.
His idea officer was not motivated by the quest for individual glory, but, having learned to command as well as to obey, would consider himself first and foremost as a professional serving his community.