What of preventive war? Fifty years after Eisenhower rejected it, George W. Bush brought it back in his invasion of Iraq. While the Bush administration called it “preemptive war,” this was a misnomer given the absence of any imminent threat. The war was really preventive, the idea being that the overthrow of Saddam Hussein would keep him from developing nuclear weapons and would somehow create a less permissive environment for the future growth and sustenance of terrorist networks. There is little need to detail the costly failure of this preventive campaign, beyond noting that today the U.S. military is out of Iraq, al Qaeda is back, and that tortured land has become a hothouse environment for the growth of violent extremism.

With deterrence on life support, and preventive war fully discredited, preemption is the world’s last, best hope for security. While it is a concept that proved poorly suited to strategies for the use of weapons of mass destruction, an era of “mass disruption” caused by small terrorist cells and hacker networks cries out for preemption. A raid on a terrorist training camp or safe house, a cyberstrike on a malicious, hacker-controlled robot network, these are the ways in which preemption can be used to reduce the threats that so imperil our world.

The beauty of the kind of preemptive operations that are possible today lies in the very low material costs of such a strategy. The challenge lies in the need for knowledge — indeed, increasing knowledge over time — to enable these sorts of strikes to be conducted. And the fact that preemption can only function on the basis of accurate insight should make the case for governments around the world to continue to amass and employ big data to search out the small cells that bedevil our era. One can only hope that the mass publics of the world will come to see the purpose, and the promise, of the information systems that support the only pillar of international security still standing.