The Paris attacks and subsequent investigation leave no doubt that jihadists were preparing coordinated aggression against the West and that many sleeper cells remain. Recent ISIS propaganda videos threaten New York City and other American targets.

Senator Lindsey Graham and his hawkish colleagues are urging that U.S. ground forces be sent to Syria to attack ISIS. “If we don’t do these things soon,” Graham avers, “what you’ve seen in Paris is coming to America.”

But would American “boots on the ground” end the threat? It’s hard to avoid skepticism, given that ISIS emerged from the ashes of failed U.S. policies—first in Iraq, through the misguided support of a prime minister who alienated the Sunni majority, and second in Syria, through the arming of anti-Assad rebels who have eagerly joined the ranks of ISIS.

More to the point, the cauldron of Syria and Iraq, with its strange brew of sectarian, cultural, economic, and ideological conflicts, is too potent to cure with anything concocted in Washington, D.C. As defense analyst Daniel L. Davis writes in The National Interest, “That toxic mix is not going to be solved by deploying U.S. ground troops.”

But if American troops are not the solution, what can be done? One answer might lie in a forgotten provision of the Constitution: Congress’s enumerated power to “grant Letters of Marque and Reprisal.” These are legal documents authorizing a private person or entity—privateers—to use force to protect against enemies of the issuing nation.

Privateering played a critical role in the America Revolution. Approximately seven hundred ships were commissioned as privateers, and they neutralized almost as many British vessels. Although they were authorized to sell captured vessels through court proceedings, they had to do so lawfully. If they could not prove the enemy status of a vessel or if they used unreasonable methods, they could be liable for damages.

Congress last issued letters of marque and reprisal during the War of 1812. Privateering lost favor as the U.S. government grew and its financial power to equip warships increased and as naval and maritime technology improved. More significantly, perhaps, the government’s career military men saw the enormous success of privateering as a direct threat to their job security

With the advent of fourth-generation warfare, it is now time to consider the reauthorization of privateering. Fourth-generation warfare recognizes that wars do not pit only one nation state against another. Terrorists armed with advanced technology now blur the boundaries that had separated war and politics, combatants and civilians.

Terrorists employ creative methods to inflict brutality and death, but the civilized world has not responded with an innovative response. Allowing privateers would encourage such a response. Congress or private charities could reward entrepreneurs who hack terrorist communication networks, locate stashes of assets, or uncover terrorist cells hiding in our cities.

Evidence that economic incentives could help in the fight against terrorism can be seen in America’s thriving bounty-hunting industry. In the criminal justice system, bounty hunters have a proven record of catching fugitives and bail-jumpers more often than when only government police are involved. They must, of course, follow rules laid down by the authorities. Congress could craft similar rules to ensure that anti-terrorism privateers remain accountable.

The State Department has used bounties on a small scale with much success. Since the inception of the Counter-Terrorism Rewards Program in 1984, more than $125 million has been paid to over 80 individuals who have prevented terrorist attacks or brought terrorists to justice. The most infamous culprits: Saddam Hussein’s sons, Uday and Qusay, and Ramzi Yousef , a leader in the 1993 attack against the World Trade Center.

History shows that private operatives can succeed where government troops fail. Businessman H. Ross Perot used his private funds to rescue his workers trapped in Ayatollah Khomeini’s Iran, when President Carter’s efforts to end the hostage crisis met with failure. Security firms such as G4S, DynCorp, and Control Risks demonstrate impressive capability, but why not broaden the scope in the war against terrorists? Allowing more private security firms to deploy their equipment and know-how would go a long way toward putting terrorist groups on the dustbin of history.

It’s time that we let them.