It is the Soldier, not the minister
Who has given us freedom of religion.It is the Soldier, not the reporter
Who has given us freedom of the press.It is the Soldier, not the poet
Who has given us freedom of speech.
It goes on like this for some time, but you can get the basic idea here. I am generally of the philosophy that you shouldn't get much credit for fixing something you broke in the first place. And indeed, all of the benefits the author claims as the byproduct of the military require similar armed coercion to remove them in the first place. Indeed, the more present the military is in public life, the less free the society tends to be, as any citizen of Burma or North Korea could tell you. Which they won't because, well, you know.
Individual soldiers may well believe in their mission as entirely benevolent crusaders for all sorts of high-minded enlightened causes. As a unit, though, their actions are entirely controlled by an absolute hierarchy ending with the government at the top. They are no more and no less than the muscle behind the Gummit's interests and are completely dependent on the state for moral direction, or the lack of it. Thus, this poem attributes a philosophical independence to the military which doesn't exist, and would be highly dangerous if it did. Conservatives, I suspect, know this, which explains the paradox between condemning Big Gummit while enthusiastically backing the Gummit's Hammer. They hold out hope such a break will occur and save them from the unfortunate democratic impulses of their fellow citizens.
Smedley Darlington Butler gave a much better summary of the soldier's duty in 1935.
I spent 33 years and four months in active military service and during that period I spent most of my time as a high class muscle man for Big Business, for Wall Street and the bankers. In short, I was a racketeer, a gangster for capitalism. I helped make Mexico and especially Tampico safe for American oil interests in 1914. I helped make Haiti and Cuba a decent place for the National City Bank boys to collect revenues in. I helped in the raping of half a dozen Central American republics for the benefit of Wall Street. I helped purify Nicaragua for the International Banking House of Brown Brothers in 1902-1912. I brought light to the Dominican Republic for the American sugar interests in 1916. I helped make Honduras right for the American fruit companies in 1903. In China in 1927 I helped see to it that Standard Oil went on its way unmolested. Looking back on it, I might have given Al Capone a few hints. The best he could do was to operate his racket in three districts. I operated on three continents.