Growing concern surrounds a new national security threat, an insidious trend that could foster terrorism worldwide and draw the U.S. military into messy regional conflicts in Africa, Asia and Latin America.
No, it is not nuclear proliferation. Nor is it a new brand of religious fundamentalism.
It is global warming.
In the last few weeks, several groups _ including the U.S. Congress, a panel of retired top-ranking military officers and the U.N. Security Council _ have considered the possibility that global warming may be a significant threat to peace and security in coming decades.
"Climate change can act as a threat multiplier for instability in some of the most volatile regions of the world," the former military leaders warned in a report released this month by the CNA Corporation, a nonprofit research consultant to the federal government. "The increasing risks from climate change should be addressed now because they will almost certainly get worse if we delay."
Droughts, crop failures and tropical disease epidemics caused by global warming could destabilize already fragile governments in Asia, Latin America and especially Africa, creating the kinds of "failed states" that harbor Al Qaida and other terrorist groups. Sea-level rise could scatter refugees by the millions from low-lying countries like Bangladesh and Vietnam, putting stress on both them and their neighbors.
A day after the report's release, diplomats were discussing global warming in a special session of the U.N. Security Council, a body more accustomed to considering war crimes and weapons of mass destruction than carbon dioxide levels and crop yields.
"This is an issue that threatens the peace and security of the whole planet," said British Foreign Secretary Margaret Beckett.
But some members of the Security Council, as well as many developing countries, objected to the discussion. They argued that global warming would be better addressed by the General Assembly _ a more democratic but less powerful arm of the U.N.
"Climate change may have certain security implications, but generally speaking it is in essence an issue of sustainable development," said Chinese ambassador Liu Zhenmin.
The next day on Capitol Hill, before the inaugural hearing of a special new House committee dedicated to global warming and energy policy, Republican Rep. James Sensenbrenner of Wisconsin expressed similar skepticism.
"I will have many questions about why global warming has suddenly become an issue of national defense," Sensenbrenner said. Later in the hearing he complained that alarmism over climate change is unnecessarily frightening America's children.
Even with all the recent dire prognostications, it is doubtful that today's children worry about climate change the same way their parents and grandparents did about nuclear annihilation. So is global warming a national security issue?
It depends on how you look at it. On the one hand, global warming is not going to invade one of America's allies or bring nuclear warheads raining down on its major cities. But it is likely to aggravate a lot of the same situations that are causing conflict in the world today.
The conflict in Darfur is a perfect example. Nomadic tribes in western Sudan are attacking their sedentary neighbors partly because drought in the region has forced them off their traditional grazing lands.
Global warming is going to cause a lot more situations like the one in Darfur, scientists predict, many of them in some of the world's hottest hotspots:
Parts of sub-Saharan Africa, already the poorest region in the world, could see a 50 percent reduction in crop yields by 2020, according to a report issued this month by the U.N. Intergovernmental Panel on Climate Change.
Decreased rainfall in Pakistan, a critical nexus in the war on terror, could devastate that nation's cotton crops and thus its largest industry of textile production, said Phil Clapp, president of the National Environmental Trust.
Chinese scientists announced this week that global warming will significantly shrink Himalayan glaciers by 2030, decreasing the flow of the Yangtze, Ganges and Mekong rivers and threatening water supplies to some of the world's fastest-growing economies.
Skeptics argue that such problems are primarily environmental, economic and social, and should be dealt with as such. Perhaps they are right. But global warming, not to mention the effort to mitigate it, promises to be so transformative that it will touch every policy realm governments deal with.
Because global warming is caused primarily by the consumption of fossil fuels, it is an energy issue. And because energy drives the global economy, global warming is an economic issue as well. It is a social issue, because it is going to affect how we live.
It is a foreign policy issue, because limiting the buildup of greenhouse gases in the atmosphere is going to require an unprecedented level of international cooperation.
And if you believe former U.S. Vice President Al Gore, global warming is above all a moral issue. At every stop on the global warming roadshow made famous by the Oscar-winning documentary "An Inconvenient Truth," Gore says we owe it to our children and to the planet itself to do everything we can to stop global warming.
Last week Gore delivered his talk at a synagogue in Indianapolis, where he made global warming sound very much like a national security threat and the moral equivalent of war.
"This is our home," he said. "We will make our stand here on behalf of our children."