Network” is the word most often used to describe terrorist organizations since 9/11. Yet, nearly six years into the first great armed conflict between nations and networks, the nations are still fighting the last war. There has been hardly a hint that the pursuit of al Qaeda and its allies is guided by any serious thinking about the new types of problems posed by adversaries who operate in small, interconnected bands, with minimal central control.

Nations still think primarily in terms of massing ponderous field forces and striking with “overwhelming force,” as the U.S. military has tried to do in Iraq. But the networks there have deflected the punches easily, pursuing their nettlesome insurgency with ever greater savagery. In this new type of conflict—call it “netwar”—the basic dynamic is one of “hiders” and “seekers.” Gone are the days of mutually massed forces clashing on a darkling plain. Now, if you can’t find, you can’t fight.

If nations are to have any hope of ultimately defeating terrorism, they must understand networks as a distinct organizational form, not just a handy labeling device. In practical terms, that means targeting network nodes, not simply trying to thwart them by invading or bombarding nations suspected of supporting them.

You can’t attack a network with a field army. Instead, it takes a willingness to field a nimble, networked force of your own. Ironically, the U.S. military actually started the war on terror in a networked way when just 11 Special Forces “A teams”—fewer than 200 troops overall—toppled the Taliban and put al Qaeda on the run. Each team was interconnected to the other, and to attack aircraft above them. They proved unstoppable.

But since late in 2001, senior U.S. generals have reasserted their...