Difficult choices coming from looming fiscal slowdown

"Hunter's letter highlights the issues confronting us," Lynn said. "Our future security is inextricability tied to the research we produce, nevertheless we are entering a period of significant resource constraints.

The past decade

"For the past decade, we have lived in a world where when we faced new security challenges, we could meet them with increased resources," Lynn said. "We have lived in a world where when we wanted to build systems with new research, like Hunter's bomber, we could increase our budget.

He noted that the United States and nearly all of its European allies are experiencing a significant fiscal crisis that requires everything to be on the table - including earnings, entitlements, domestic discretionary spending and defense spending - in regaining solid financial footing.

"By pure efficiencies, I mean where you perform the same function for less money," he explained. "To illustrate, cloud computing holds out the potential of generating greater capability at lower cost across our information innovation enterprise. However we are not going to find enough pure productivity gains to generate all the required savings. This means that we have to prioritize. We will have to eliminate programs thatare not valuable enough to sustain in this budget environment."