The issue is whether "army" is a proper noun. I capitalized it to show respect to the men and women who serve our country. He lowercased it, because there is more than one army in the world.
This is one of those nit-picky details that can drive you crazy, so I emailed a friend who has a "retired Army" sticker on his mini-van, and asked him the question.
He answered in a large, colorful font; "Army is ALWAYS capatilized."
Sir, yes, sir!
But the question is still nagging me.
I know that Marines is always capitalized because there is only one branch with that name in the world. "He was a Marine."
There's more than one army in the world.
So, if the word 'the' is in front of it, then "United States" is implied, making it proper.
Join the (United States) Army and be the best that you can be.
If 'the' does not precede the word, then it is a common noun. "He was wearing army boots." There is more than one army, and all armies wear boots. In this case, the noun is common.
So, take up your weapons and aim at the subject. Is Army a common or proper noun