Tyler Cowen discusses the use of military contractors:
It is easy to rail against contractors for holding money above loyalty to country; Halliburton, for instance, has been a target of this criticism. But money isn’t the real issue. Few Americans would join the armed services without pay, and most American weapons are made by the private sector for profit.
Furthermore, privateers, private ships licensed to carry out warfare, helped win the American Revolution and the War of 1812. In World War II, the Flying Tigers, American fighter pilots hired by the government of Chiang Kai-shek, helped defeat the Japanese. Today, many of our allies receive payment, either implicitly or explicitly, to support American efforts. War is, among other things, an economic undertaking, so the profit motive in military affairs isn’t always bad or ignoble.
When it comes to supplying troops, or protecting high-ranking officials, private military contractors often offer greater flexibility and rapidity of response. The employees, many of whom are former soldiers or operatives, tend to have more experience than current, mostly younger soldiers.
For more on this topic, check out Alex Tabarrok’s “The Rise, Fall, and Rise Again of Privateers.“