Recent news has brought nuclear weapons back into the political picture, just as a new report suggests that the United States will have difficulty denying nuclear weapons to regional powers that seek them.

Sen. Hillary Clinton recently confirmed that as president she would be willing to use nuclear weapons against Iran if it were to launch a nuclear attack against Israel. In an interview Mrs. Clinton affirmed that she would warn Iran’s leaders that “their use of nuclear weapons against Israel would provoke a nuclear response from the United States.”

And last week the Bush administration told Congress that North Korea was helping Syria build a plutonium-producing nuclear reactor before Israel bombed the site last September.

Such news assumes that efforts at preventing nuclear proliferation will be, at least partially, unsuccessful. This is why a new report from the RAND Corporation says, “prudence dictates that the United States and it allies prepared for the possibility that they might, in the not-too-distant future, confront regional adversaries with deliverable nuclear arsenals.”

The monograph, “The Challenge of Nuclear-Armed Regional Adversaries” released April 15, 2008 was written by RAND analysts David Ochmanek and Lowell H. Schwartz. Ochmanek is a former Air Force officer and served as Deputy Assistant Secretary of Defense for Strategy from 1993 until June 1995. Before coming to RAND, Schwartz was a former business analyst at The Boeing Company.

The authors take exception to the view that deterrence is still a valid strategy, as it was against the Soviet Union during the Cold War. They argue that deterring the use of nuclear weapons by threatening retaliation could be “highly problematic in many plausible conflict situations involving nuclear-armed regional adversaries for the simple reason that adversary leaders may not believe that they will personally be any worse off for having used nuclear weapons than if they were to forgo their use.”

The authors write that for different reasons — Kim Jong Il out of a sense that he has little to lose and Iran’s leadership out of nationalist ambition fueled by religious-revolutionary zeal.Both countries may be willing to accept a great deal of risk once conflict breaks out.

The monograph points out North Korean and Iranian leaders have compelling reasons to consider using nuclear weapons. It notes:

The prospect of the United States forcibly overthrowing them is not an abstract proposition. Both of the U.S. national security strategy documents released by George W. Bush declared that the ultimate goal of the United States is “ending tyranny.” And both North Korea and Iran are cited as examples of the types of regimes about which the United States harbors grave concerns.

And, given that the leaders of such “regional adversary states” recognize that their military forces are locked into a position of marked inferiority against U.S. conventional forces they cannot prevent large-scale U.S. forces from deploying to their regions or mounting an attack. The report states if diplomacy fails, over the next 10 years, they could field between a dozen and three dozen fission weapons.

In fact, they might even be tempted to use them early on in any conflict. This would be a scenario the United States has never before confronted. The monograph states that in certain circumstances U.S. leaders can not be confident of deterring regional adversaries from using their limited arsenals, even if the United States maintains its nuclear superiority.

Politically, such a conclusion is likely to bolster the support for hard-liners in the Bush administration and Congress who argue against trying to negotiate with North Korea and Iran over their nuclear programs.

The monograph states that the United States and allied leaders confronting nuclear armed adversaries will want “military capabilities that offer far greater assurance than do today’s that adversaries can be prevented (as opposed to deterred) from using nuclear weapons.”

This means forces that can locate, track, and destroy nuclear weapons and their delivery means before they are launched, as in a pre-emptive attack and, above all, active defenses, meaning missile defenses, that can destroy delivery vehicles after they have been launched. The monograph calls for fielding effective defenses against theater-range missiles, not ICBMs.

But the report notes that even theater defenses have limitations. The Patriot air defense system, for example, has a small footprint, making it impractical to defend large populated areas with such systems. And any thin deployment of missile defenses can be overwhelmed by modest-sized (10-to-20 missile) salvo attacks.

For policymakers, the monograph’s conclusions mean a return to tradition for U.S. leaders. It states that:

unless the United States and its allies can develop and deploy capabilities that can prevent regional adversaries from employing nuclear weapons (as opposed to trying to deter them from doing so), future power-projection operations will likely revert from the post–Cold War model of “decisive defeat” back toward concepts incorporating elements that were prevalent in military planning during the Cold War: limited war and escalation management.

Such language sounds more innocuous but it isn’t. It was Cold War theories of “limited war” that caused the United States to develop tens of thousands of nuclear weapons during the Cold War in an effort to maintain “escalation dominance” while avoiding a full fledged nation destroying nuclear war with the Soviet Union. This is one tradition the United States should reject.