For better or worse, western intelligence agencies spare no expense in trying to gather information on hostile regimes and their leaders. This has led to a at least three “cottage industries” in the intel business, focusing on human factors, psychological profiling and medical intelligence related to world leaders.

During my spook career, I had a chance to work with (or at least converse) with professionals in each of those endeavors. While I certainly respect their work, there was always the nagging suspicion that such “analysis” was more alchemy than science. After all, who can explain the vagaries of a complex personality like Saddam Hussein? Before August 1990, the human factors teams and psychological profilers certainly recognized the sinister (and opportunistic) elements of Saddam’s psyche, which translated into a brutal and oppressive regime. But despite our recognition of those traits, no one saw their ultimate manifestation in the invasions of Iran (1980) and Kuwait ten years later.

The same holds true for medical intelligence assessments of global leaders. Late last year, then-Director of National Intelligence John Negroponte suggested that Cuba’s Fidel Castro was (literally) at death’s door. There were even reports of parties in Miami’s Cuban-American community, celebrating the impending demise of El Comm andante.

Flash forward six months, and it appears that reports of Castro’s imminent death were premature, at best. True, the Cuban dictator hasn’t resumed day-to-day management of The Workers Paradise in the Caribbean, but at last check, he was still alive and apparently in command of his faculties. Those celebrations in Little Havana are apparently on hold, at least for now.

Castro’s apparent recovery from an intestinal condition (or at least the stabilization of his condition) underscore the difficulties in assessing the health of a head-of-state. For starters, such information is a closely-guarded secret, particularly in dictatorships where concerns about internal threats and regime preservation are paramount. Aside from a few propaganda videos from Cuba’s state media (and some silly statements from Hugo Chavez about Fidel’s amazing recovery), we didn’t hear much about how sick–or well–Castro really was. We face similar problems in trying to learn about potential health problems among the leadership of Iran, North Korea and Syria, just to name a few places.

So how do we assemble those medical profiles? From a variety of sources. Video of a leader delivering a stem-winder speech may reveal tremors (or other physical symptoms) associated with Parkinson’s Disease, or other neurological disorders. Television and still images can also reveal other changes in appearance (such as rapid weight gain or loss), which might suggest other physiological conditions.

We can also glean evidence from defectors or opposition groups, who may have access to medical information, though such data is often second-hand and appropriately suspect. However, these sources can sometimes steer us toward the “foreign” doctors and specialists who are often imported to care for an ailing dictator. Castro’s intestinal surgery last year was reportedly performed by a Spanish physician. If we can debrief the “imported” doctor–or perhaps a confidant–we can gain additional insights into the patient’s condition.

And, in the information age, there are also certain (ahem) tools that may allow us to “mine” medical data from selected sources. But even those capabilities are limited. Treating patients like Castro, foreign doctors are carefully controlled in their movements, record-taking and communication. It’s likely that the Spanish surgeon was not allowed to carry any information on Castro’s condition out of the country, except for the data stored in his brain. Factor in the human tendency to forget things, potential sympathy to Cuban cause and doctor-patient confidentiality rules, and it seems likely that Castro’s “imported” physician didn’t provide any meaningful information on his condition or prognosis.

That’s why we should take reports about Kim Jong-il’s deteriorating health with a grain of salt. According to NBC News, U.S. and South Korean intelligence officials are “taking seriously” claims that the North Korean dictator is suffering from high blood pressure and advanced diabetes. Reports of Kim’s possible health problems first surfaced last month, in South Korea’s Chosen Ilbo newspaper last month, and were based on information from the ROK National Intelligence Service. Quoting an anonymous government official, the paper said that Kim’s diabetes and heart problems had worsened, and that the information was “more reliable” than former rumors.

As evidence of Kim’ s supposedly-declining health, intel agencies in the U.S. and South Korea have noted a decrease in the North Korean leader’s public appearances. Chosen Ilbo claims that Kim’s public activities are at about “half the level” of a year ago; he hasn’t been seen publicly since late April and his last reported public appearance (on 5 May) wasn’t carried on North Korean state television.

However, there are other possible explanations for Kim’s sudden absence. He’s disappeared for extended periods before, most notably, after the death of his father, Kim Il-Sung in 1994. That touched off speculation that the younger Kim was having trouble in cementing his hold on power, or that some sort of internal struggle might be underway. Eventually, Kim Jong-il reemerged and demonstrated that he was fully in charge of the regime.

At age 66, it’s doubtful that Kim Jong-il is in the pink of health. He’s a big fan of Dunhill cigarettes and Hennessy cognac, and reported trips to that multi-story “Pleasure Palace” in Pyongyang have (perhaps) taken a toll as well. But, while U.S. intel official told NBC that there are concerns about Kim’s health, he believes it’s unlikely that Kim is on his death bed. We’ll second that notion, with the caveat that medical intelligence on dictators and despots is often exaggerated, and rarely accurate.