Evidence-based Medicine: Lessons for Foreign Policy

What lessons does evidence-based medicine hold for Foreign Policy?

Galen examining an injured gladiator. Image from Science Photo Library.  

The dawn of evidence-based medicine offers an interesting case study for the opportunities and challenges of institutionalizing expertise in the field of foreign policy.

Medicine was, for thousands of years, the provenance of intuition and gut instinct. Galen, a second-century physician to the Roman emperor, wrote some of the foundational descriptions of human anatomy and medicine that remained influential for over a thousand years. Yet Galen’s understanding of medicine was decidedly pre-scientific: “All who drink of this treatment recover of a short time, except those whom it does not help, who all die. It is obvious, therefore, that it only fails in incurable cases.”

Nearly 1,700 years later, in 1799, George Washington’s doctors were little better. They had convinced themselves of the wisdom of a variety of brutal interventions to cure their ailing general. In his final 12 hours, the doctors induced in Washington massive bloodletting – roughly 40% of his total blood volume – raised blood blisters on his skin, and induced vomiting and diarrhea with mercury. Like Galen, the doctors believed bloodletting would help Washington recover, unless he was incurable, in which case he would die.

Sound familiar? Such sentiments are common in foreign policy today. Successful policy interventions are credited to master statesmen, while failure is blamed on incurable diseases like Vladimir Putin or Kim Jong-un. The shared logic is that the fault must lie in the patient’s weakness, not the doctor's.

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James Lind's work with citrus to cure scurvy was perhaps the first reported clinical trials in medicine. Photo credit: Institute of Royal Medicine.

Doctors might have discovered more intelligent and effective approaches to treatment had they taken a lesson from James Lind, a British ship doctor who discovered the cure to scurvy through clever experimentation in 1747. Lind identified a dozen afflicted sailors and gave each a different treatment: vinegar, seawater, bark paste, citrus, and more. The sailors given citrus recovered quickly compared to the other interventions.

John Snow’s discovery of cholera’s cause in 1854 offered another opportunity for the medical profession to update its methods. Snow painstakingly mapped London’s water distribution systems to identify correlations with outbreaks of cholera. He produced convincing data that residents exposed to Company A’s water were likely to get cholera, while neighbors who received water from Company B’s water were spared. Snow demonstrated that two companies' water systems were randomly distributed throughout the city, resulting in no systematic differences between those who received water from one company or another except that Company A’s water was contaminated with Cholera – a perfect natural experiment with treatment and control conditions. Snow convinced city officials to halt the distribution of tainted water, saving countless lives, and cementing his status as one of the founders of epidemiology.

It was not until after WWII, one hundred years later, that medical trials started to grow in popularity. Even still, the medical profession aggressively resisted the uptake of scientific evidence and evaluation. Physicians stubbornly insisted that their intuition and experience were the only valid sources of wisdom. Science skeptics asserted that each patient was unique, and thus scientific evaluation was useless. They even suggested such testing was dangerous and unethical because it could subvert a physician’s instincts.

The innovative doctor Archie Cochrane despised this attitude. He called it the “God complex.” Though he was ridiculed for advocating for evidence-based medicine, Cochrane persisted, frustrated that the annals of medical history were littered with “miracle” cures that were proven harmful: the use of cocaine and heroin to cure cough, lobotomies to address mental health, mercury for syphilis, bloodletting to flush impurities, drinking radioactive water to strengthen immunity, and much more.

Working for the British health service, Cochrane railed that doctors demonstrated “far too little interest in proving and promoting what was effective.” He was furious at the extent to which unsubstantiated claims plagued medicine and could proliferate throughout hospital systems. 

Cochrane believed a medical intervention could only be considered “effective” if it had been demonstrated that it did more good than harm. He believed that simply developing extensive knowledge about the human body is insufficient for medical expertise. One must also constantly study the efficacy of medical interventions to differentiate the miracle drug from snake oil.

Cochrane’s research and advocacy led him to be dubbed the founder of evidence-based medicine. However, his methods did not take hold until the 1970s. You read that correctly: the evidenced-based medicine movement did not take hold until the 1970s! Even still, Cochrane’s fight remains unfinished even today: “When evidence says no, but doctors say yes.”

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Some readers may reject the comparison between medicine and foreign policy. Certainly, they are not perfect analogs. The science of human biology, epidemiology, and physiology are in many respects more mature than the science of foreign policy. Untangling the mysteries of the human body is easier in some ways than researching foreign policy: each human body is relatively alike, illness affects different bodies in similar ways, and billions of bodies can be studied. If a treatment works in a population of 100 individuals, it is a good bet that it will scale to the rest of the human species. The triumphs of modern science – the eradication of smallpox, for instance – have little obvious equivalence in foreign policy.

But it is important to acknowledge the way our society holds trust for medical science while recognizing its obvious shortcomings. Hundreds of billions of dollars have been invested in cancer research alone in recent decades, yet the cancer death rate has only fallen by 1% a year since 1990. When a relatively common knee injury forced me to consider surgery a few years ago, I was unsurprised to receive an entirely different treatment recommendation from each of the four doctors I consulted. The rapid development of Covid vaccines did not overshadow just how flummoxed our medical profession was by the virus in its early days; we still seem to know relatively little about how Covid – which killed seven million people and afflicted nearly 700 million– affects the human body. 

Most medical scientists would admit that our ignorance about the human body and its infinite variations towers over the sum of our knowledge. Yet, while nobody would dispute the myriad weaknesses of modern medicine, the value of its continued pursuit is virtually unquestioned in our society. 

I hope we can develop a similar attitude toward the science of foreign policy.  

One can admit that the study of international relations presents unique research challenges. The ability of researchers to conduct controlled experiments is limited, the population of states is small compared with the population of human bodies, and the number of forces acting within the international system is dazzlingly complex.

Yet, if we allow these challenges to lead us to reject the utility of science, or stand in the way of its progress, we will do our profession a dangerous disservice. We must aspire to be a little less like George Washington’s doctors and a little more like John Snow and Archie Cochrane as we steer our field toward a brighter future. Change is hard — but it is necessary to keep pace with a changing world.