If terrorism recedes as the central defining question of contemporary international relations, will "natural security" rise to take its place? This was the subject not only of today's column at World Politics Review, but a topic extensively discussed yesterday at a panel at the Carnegie Council on Ethics and International Affairs in New York.

My thinking on these matters has been influenced by pieces written by Thom Shanker, Lester Brown and Michael Kugelman, among others. Yesterday's discussion, with David Speedie, Dov Waxman and Devin Stewart (who has posted a link to his remarks) laid out what I see as a possible "vicious circle" emerging: revolts in the Middle East (and possibly elsewhere in the world) are linked to rising food prices and concerns about achieving (or retaining) a middle class lifestyle. Dov noted that in the region, food prices increased by 32 percent over the last year--and wages and opportunities are not expanding at similar levels. The Japan tsunami highlights climate change dangers, but the nuclear crisis calls into question whether atomic energy will be used to provide new sources of power--and demand for energy is rising. The Middle East is likely to remain unstable for the foreseeable future--leading to increased prices for oil. And then we come back to food prices: the growing trend to diverting agricultural products for fuel production rather than food--which means when oil prices go up, food prices go up (not only because of the oil inputs to power agricultural machinery and produce fertilizer but because more grains are diverted to produce ethanol). Food prices go up--further leading to tensions in the Middle East, while climate change affects agricultural production, especially in terms of water usage. Desalination plants--for the Middle East in particular to replace rapidly-draining aquifers--need power--but if nuclear energy is out of favor, then what? And so all these factors reinforce each other in helping to promote greater instability ...