I can't help but think your logic is seriously flawed. Having been in a battlefield I can attest that living in the US is not even remotely similar to a battlefield.
In fact we have the 2nd amendment to prevent the US from turning into a battlefield. The purpose of the 2nd amendment is so that we can protect ourselves and our loved ones from violent criminals so that crime is kept under control and does not rise to the terrible levels as we see in the UK.
The 2nd amendment also gives us the ability to defend our society and country from enemies both foreign and domestic.
There is some question as to the validity of the quotation, but Japanese Admiral Isoroku Yamamoto has been reported as saying, "You cannot invade the mainland United States. There would be a rifle behind every blade of grass."
He may not have said exactly that, but if he did he would have been right. It has been estimated there are 30,000,000 gun owners in the US, owning 270,000,000 guns. If just half of us stood against an enemy we would be the largest army in the world with 15,000,000 willing members, most of whom are military veterans, and virtually all are trained and practice basic shooting skills on a regular basis.
There are currently 2,500,000 persons in our military including active duty, reserve, and National Guard units. In other words there are 6 times as many gun owners ready and able to defend our country than there are military personal.