Leaders of these mentioned states desire greater regional influence, and most importantly: they want to stay in power. I thought Record's article hit on a key point when he said that "Saddam loved himself, more than he hated the United States." Why would Saddam act irrationally, provoking military occupation by the U.S.? Further though, every leader is accountable to his/her citizenry. There is a relative scale to this accountability, but I hypothesize that accountability does exist in every government. And accountability increases if the populaiton of these countries fear the U.S. more than they do their oppressive governments. In this environment, accountability creates fertile ground for deterrence.
For example, the United States is on one extreme of the scale where citizens can remove officials from office through our democratic elections. Thus, foreign policy is crafted with popular opinion, and often moderate. On the other extreme, are "wreckless countries" whose leaders are accused of trying to deliver terrorist organizations nuclear weapons. These countries do often have fiery rhetoric, but actions are somewhat predictable still. Iraq, Myannmar, Iran and North Korea spring to mind as often-cited regimes that threaten the safety of its people by what is seen as suicidal foreign policy.
Many would say that these governments are not accountable to their people, but that is only as long as the threat by them is greater than the threat from a reactionary United States. Regimes will lose power if they act with too much aggression or empower non-state actors with nuclear weapons. One, how long could a handler "handle" a proxy nuclear force? Further, how would a citizenry react when they found out that their government gave nuclear weapons to a terrorist organization, drawing the ire of the most powerful country on the planet, the United States?
Regimes do not necessary have to be afraid of the United States as long as the masses of that country are. Saddam could have had plans for global expansion and an arrogance about U.S. power. However, if he would have acted out of order, not only would we have responded, but his people would have raised in opposition towards him. Deterrence is not just merely between states, but also between civil society- and their respective state. Once, a "irrational" leader would act out of line, he would be responded to not only be the United States, but by his country's constituents. Today, detterence is easier than it was in the era of WWII. Nuclear weapons are a well-known entity in our cache of responses. Further, the United States can respond to "maniac madmen" like Saddam without ever setting a foot within their country due to the advent of offensive-drones. Deterrence is now, I believe, more likely than ever as the United States has never been stronger and the world's people have never been more hungry for peace, stability and a relatively good life, void of conflict, especially with the United States.
This does not conflict with the idea that movements such as Al-Qaeda or Japan's Aum Shinrikyo. These types of organizations lack a constituency and internationally recognized legitimacy. Thus, these terrorist organizations are not susceptible to the type of dual deterrence I espoused within this post.