Michael McConnell, the director of national intelligence, predicted rising demand for scarce supplies of food and fuel, strategic competition over new technologies, and the spread of weapons of mass destruction.

"What I'm suggesting -- there's an increased potential for conflict," McConnell said in a speech Thursday to intelligence professionals in Nashville, Tennessee.

"During the period of this assessment, out to 2025, the probability for conflict between nations and within nation-state entities will be greater," he said.

Conditions for "large casualty terrorist attacks using chemical, biological, or less likely, nuclear materials" also will increase during that period, he said.

McConnell described a multi-polar world in 2025 shaped by the rise of China, India and Brazil, whose economies will by then match those of the western industrial states.