This week's column space did not allow the proper amount of space for Jonathan Stevenson, author of the award-winning Learning from the Cold War: Rebuilding America's Strategic Vision for the 21st Century (Penguin), to address the complexity of, arguably, the most important diplomatic challenge facing the planet: nuclear arms. The following is the full exchange that I had with Prof. Stevenson.

One final, late-breaking note about the safety and security of Pakistan's nuclear arsenal. A chilling and timely article by Seymour M. Hersh in the Nov. 16, 2009 issue of The New Yorker indicates that the arsenal may not be as safe as the rest of the world hopes.

Hartford Advocate: We have had what is rightfully perceived as a "sea change" election in the U.S. Has it made any difference in the threat of nuclear proliferation?

Jonathan Stevenson: Though certainly a "sea change" in our nation's history, the election of Barack Obama so far does not seem to have affected a comparable shift in the threat of nuclear proliferation. His desire to "get to zero" has certainly inspired more talk of nuclear abolition from serious players--including people like Ivo Daalder, the U.S. ambassador to NATO. But Iran still appears unwilling to curb its ambitions to develop a nuclear weapons capability, while North Korea also seems intransigent about advancing its capability, and those tow countries remain the biggest threats to the non-proliferation regime.

HA: President Obama has clearly made this a priority. In April, he gave a speech in Prague and in September he chaired a summit at the UN Security Council, which approved his resolution about achieving "a world without nuclear weapons" and urged all countries to sign the 1970 nuclear Non-Proliferation Treaty. All positive steps, of course, but is there anything concrete to show for it?

JS: The mood music between the United States and Russia--given their vastly superior nuclear arsenals, by far the two most important countries in the nuclear arena--has undoubtedly improved on the heels of President Obama's speech, owing to a concerted effort on the part of the administration to "reset" U.S.-Soviet relations. Perhaps the most substantial incentive Moscow to work with the U.S. has been the Obama administration's downgrading of missile-defense in Eastern Europe, the more robust Bush administration version of which Russia viewed as degrading to its nuclear deterrent and therefore provocative.In October, the US and Russia started talks in Geneva about renewing theStrategic Arms Reduction Treaty (START 1), which expires on December 5 of this year. Renewal, of course, would not constitute abolition, but an ongoing dialogue would revive the arms-control tradition that the Bush administration disdained, which is required for incremental progress towards abolition.

HA: I just read a lengthy account of where the nuke talks with Iran are at the moment. What is your sense of what's really going on? Are the Iranians stalling for time, to "sell" the idea of a nuke fuel deal with France, Russia and US, the Great Satan? Do they secretly want to reach an accord but worry how it'll go over with the "hard liners"?

JS: It's difficult to know what's really going on in the Iranian government, but nuclear issues have not appeared to divide "hardliners" and "reformers" in the past and there is no concrete indication that they are doing so now. Furthermore, the one thing that appears clear from its rejection of the deal to transfer nuclear fuel to Russia for enrichment is that domestic discord has not appreciably tempered Tehran's nuclear ambitions.

HA: Isn't the ball back in the United States' court-or, to bend the tennis metaphor, isn't it advantage U.S.-now that Iran has gone through a flawed election, is roiled by domestic unrest and its government is perceived by many as illegitimate? Or does this "wounded" quality make Ahmadinejad more dangerous?

JS: On balance, the fact that the flawed election and public protests put the Ahmadenijad government on the defensive domestically probably made it harder to deal with internationally. Signals that this is the case include not only recalcitrance on nuclear matters but also Iran's ongoing political and material support for Hezbollah and Hamas. More broadly, it's common for illiberal regimes to amplify external threats and problems to distract the domestic population from difficulties closer to home.

HA: What do they mean when they say this nuke fuel that Iran wants will be used to "produce radioisotopes for medical purposes"? Do U.S. hospitals use nuke fuel in this way? Can the same technology be used for nuke weapons or is the road to the latter far more complicated than just having some nuke fuel and, presto, you have a bomb?

JS: The need to produce isotopes for medical purposes joins the need for an alternative energy source as what most consider Iran's disingenuous pretexts for producing nuclear fuel. With respect to the medical rationale, the reactor in question is Iran's 40-megawatt heavy water reactor in Arak. The benevolent isotopes themselves are not dangerous, but the process for producing them also yield weapons-grade plutonium as a byproduct. The Arak reactoris the same kind of reactor that India and Israel used to produce the plutonium for their weapons programs and is related one North Korea used.

HA: What is wrong with continuing to sit down with a purported "enemy"? Look what happened when Reagan and Gorbachev met in Iceland. Doesn't modern nuke talks begin with that event?

JS: There is nothing wrong with cautiously talking to one's enemy, as the Obama administration is continuing to do with Iran and North Korea. The Reagan-Gorbachev comparison, of course, is of limited applicability given that neither Ahmadinejad nor Kim Jong-Il appears to have Gorbachev's statesmanlike qualities and Reagan initially overreached and had to be reined in by his advisors (hence the emphasis on caution).

HA: Is the situation in Iran volatile enough to present worries on par with Pakistan? Pakistan seems in a much more dangerous situation. Is the Pakistani nuclear arsenal safe and secure from the religious fanatics?

JS: Pakistan already has nuclear weapons, while Iran is still moving towards a break-out capacity, so even with other things--such as the risk that nuclear weapons would fall into the hands of Islamist militants--being equal, Pakistan poses the greater present danger. That said, the conventional wisdom is that the Pakistani military has been sufficiently de-Islamized in its upper ranks that the nuclear arsenal is reasonably secure. But it's still possible that a Pakistani civilian government and military seen as too obeisant to the U.S. and other Western powers will come under greater pressure from Islamists, which is one reason the U.S. has been relatively circumspect in leaning on Pakistan to do more about the Taliban and al-Qaeda. The concerns about Iran are prospective, and there is a legitimate worry that if the "Persian" Shi'ite Muslim power gets nuclear weapons, its historic Sunni Arab rivals--in particular, Saudi Arabia--will feel compelled to get them, too, while Israel will expand its own nuclear program to bolster its deterrent against Iran, or perhaps take pre-emptive military action that could prove highly destabilizing.

HA: Another thought: If we obsess about Iran, is there a danger that we will ignore, or underestimate North Korea? And Kim will make another grab for global attention?

JS: Although divided and therefore diluted attention--e.g., between Iraq and Afghanistan--has imposed serious recent strategic costs on the United States, I think it has been able to maintain focus on both Iran and North Korea sufficiently, viewing them both as critical parts of an overarching proliferation threat. Washington's crucial strategic relationships with Japan and China, among other things, are reasonably good insurance that it will not neglect North Korea, while its key strategic relationships with Israel and the Arab states ensure due attention to Iran as well.