The problems of accountability are familiar from Iraq. Just last week, a federal court tossed convictions against three former Blackwater employees involved in a 2007 massacre in Baghdad. The court ruled that prosecutors had overreached in what they charged the men with, meaning that though no one denies the horror of the incident, the men’s sentences will be shortened or eliminated.

There is also a moral hazard involved in outsourcing American foreign policy in a way that intends to put it out of sight and out of mind. As James Fallows wrote in The Atlantic two years ago, the U.S. population is arguably already far too removed from war. Pushing those responsibilities to a private company only exacerbates the risk.

But the great mercenary hope keeps popping up for the simple reason that seems to offer the prospect of spending less while insulating American soldiers, Marines, and other service members from harm’s way. Prince, likening his prospective force to the British East India Company, which in effect ruled parts of India in the 18th and 19th centuries, argued in May:

An East India Company approach would use cheaper private solutions to fill the gaps that plague the Afghan security forces, including reliable logistics and aviation support. The U.S. military should maintain a small special-operations command presence in the country to enable it to carry out targeted strikes, with the crucial difference that the viceroy would have complete decision-making authority in the country so no time is wasted waiting for Washington to send instructions. A nimbler special-ops and contracted force like this would cost less than $10 billion per year, as opposed to the $45 billion we expect to spend in Afghanistan in 2017.

What Prince is outlining is an autonomous force that could operate without accountability either from voters, via their elected representatives, or from the prying concerns of human-rights officials in the government. On Tuesday, Prince added, “This approach would cost less than 20 percent of the $48 billion being spent in Afghanistan this year. Trump was hired to remake our government. There is no greater need for a restructuring than in Afghanistan.”

Yet the hope of a cheap force that can be forgotten about is tenuous as well. The problem is that separating American wars from American soldiers is never as easy as it sounds.

Prince says that a mercenary force would save huge sums of money. What’s unclear is how that would work. In 2009, for example, the Congressional Budget Office found that in wartime, private security costs about the same as the U.S. military. (Savings come during times of peace, because taxpayers don’t have to pay contractors then—whereas they do have to maintain a standing army.)

Additional costs enter in less obvious ways. Take the Blackwater verdicts thrown out this week. The men were handed strict sentences for using machine guns to commit a violent crime, but the judges ruled that was unfair, since the U.S. military had required the men to carry the guns. Meanwhile, the U.S. has found itself occasionally pulled into lawsuits over mercenary liabilities. When plaintiffs have tried to sue companies like Blackwater and KBR, the companies have argued that they ought to enjoy the same immunity that the military does against certain lawsuits, since they are acting in lieu of the military. In other cases, they have claimed that the U.S. government agreed to assume liability.