As I mentioned on The Panelist...

Pakistan, which has a reputation as a politically unstable country, has admitted to nuclear weapons, thus striking fear into the hearts of India's people.

North Korea has also admitted to possessing nuclear weapons, but is presumably getting ready to disarm in the face of international opposition. Around the world, most developed nations and a few developing nations possess nuclear weapons, some close to America's shores, some so distant that the fear of nukes seems scarcely worth the effort.

Until one takes terrorism into account.

Rising tensions over an undeclared and unresolved war in Iraq and another in Afghanistan bring the threat closer to home in the form of a terrorist's "dirty bomb." Food and oil shortages escalate tensions in Asia. Deteriorating relationships between major powers, and the recent Russian Victory Day display of tanks and other weapons has Germany on edge. We are, according to the U.S. Dept. of Homeland Security, right around the corner from a nuclear terrorist attack.

''As an initial indicator of this trend, a recent analysis of online jihadist documents that deal explicitly with nuclear weapons has revealed that while their knowledge is still below par, there have been significant advances in the understanding of nuclear issues within the general jihadi community in only a few short years,'' Gary Ackerman, research director for the National Consortium for the Study of Terrorism and Responses to Terrorism at the University of Maryland testified before a Congressional committee.

In the 60's and 70's, we did the drill in school - hiding under desks in the event someone dropped the "Big One." Today, we're a little more sophisticated. We know a desk may save us from a collapsing roof, but it takes a little more thought and effort to protect ourselves from those other nuclear effects, including flash blindness, radiation poisoning and the subsequent effects on water and food supplies.

These techniques, which I describe below, are also applicable in the event of a nuclear plant failure. Most U.S. nuclear plants were built in the 70's, and are now beginning to experience problems typical of aging infrastructure and somewhat primitive design. We haven't had an event since Three Mile Island in 1979, and some nuclear power experts are still waiting for the other shoe to fall. In any event, there are some things you can do to prepare for a worst-case scenario from whatever source.

First, know your state's civil defense policies, shelter locations and civil defense siren protocols. In the event of an actual nuclear attack - nuclear weapons launched via intercontinental ballistic missile (ICBM) systems - the warning would likely come from civil defense (air raid) sirens, followed by media coverage, and would potentially give citizens up to a half-hour of warning. A nuclear plant failure would likely provide the same type and amount of warning. A dirty bomb would not.

Most civil defense sirens in U.S. cities are tested on a regular basis. Know your state's test pattern. In Minnesota, it's the first Wednesday of the month. Varying tones often indicate the nature of the impending disaster. A single note, called Alert, usually sounds for tornadoes, or tsunamis in coastal areas. Attack, Wail, and Hi-lo are additional warning tones, the last often used by rescue units, police, and fire departments. Know what the tones mean, and how your state will use them to alert you.

If you hear the sirens and it's not a scheduled alert day, take shelter and assess the situation. The best place is underground.