William Lynn, the U.S. deputy secretary of defense, told executives at an aerospace and defense conference in Washington that the Quadrennial Defense Review currently in development at the Pentagon would be a "landmark" review, the U.S. Defense Department said.
"And it comes at a time when the nature of war is changing in ways that we need to adapt to," he added. "The QDR seeks to identify these changes and the challenges they present to our security."
Lynn said the threats that nation-states face from non-state actors in the current defense environment were once unthinkable as technology and non-conventional tactics grow in their use.
This, he said, translates into a demand on U.S. forces to pursue "maximum versatility" in order to advance "the ability to fight irregular conflicts."
Cyberthreats, he added, pose a unique threat to the U.S. defense infrastructure as an estimated 100 foreign intelligence organizations try to crack into the Pentagon's computer network regularly.
"It's not a future threat," he said. "The cyberthreat is here today."
Final reports to Congress on the QDR are expected in early 2010.