Well, thank goodness for governmental ineptitude. A private, decentralized "system" of defense would've neither attacked its neighbors (bad business, it's more profitable to trade in a free market), nor been relegated to inefficient use of resources simply because some top level moron doesn't know how to utilize them effectively. Multiple companies doing such a thing would require each and every CEO (or whatever title you use) to be just as incompetent. And let's not even mention the stupidity of wiping out an entire sector of the marketplace (Jews, Gypsies, homosexuals, etc. etc. ad nauseum), and thus losing many valuable potential customers.
Of course, this speculation has been brought to you by free market ideology. Because people believed that a state could grant them prosperity and a good life, they gave their taxes and didn't rise up when their monopolized-through-force "security company" decided to expand its territory. The Nazis didn't create the seat of power. They just used it in a manner consistent with its nature. Everyone should learn that fascism is the true face of government. Anything else is just window-dressing on a deadly "servant", and a terrible master.