Nuclear winter is coming. As George R.R. Martin has acknowledged, "dragons are the nuclear deterrent" in his epic fantasy. One security analyst agrees, and argues that Game of Thrones teaches us a great deal about the benefits and dangers bestowed upon nations who wield these ultimate weapons of destructions.

Writing in the Bulletin of the Atomic Scientists, Timothy Westmyer sees an immediate parallel in that both dragons and nuclear weapons offer their owners a seemingly inexpensive defense. With just three dragons and fewer than 2,000 combatants, Aegon Targaryen had previously brought most of a continent under his rule, with no time or treasure frittered away in rallying men or building fleets and armaments. Nuclear programs likewise appeal to leaders who are seeking the most bang for their buck (or "stag," in this context).

But the metaphors don't stop there:

Deterrence with dragons

Possession of a nuclear warhead does not automatically confer effective deterrence. The possessor must also have the means to deliver the weapon to a target, detonate it at the right time and place, communicate intentions to rivals, and protect its arsenal from attack.

After hatching, Daenerys' dragons are feeble and unable to fly great distances or breathe fire at higher yields. During their infant stage, her dragons behave more like tactical nuclear weapons than those suited for a strategic mission; they are only usable in a localized theater such as inside an enclosed space. Until her baby dragons grew stronger, they were vulnerable to steel or theft. Nevertheless, as long as they could survive a first strike, they could deter conflict, much like what Waltz wrote about small nuclear forces. As dragons age, their scales harden to protect against arrows, just as intercontinental ballistic missile silos eventually were hardened against anything but a direct ground burst. These are lessons every young nuclear weapon state must learn.

Nuclear deterrence is often characterized as preventing war between two or more nuclear powers. But stabilizing concepts such as mutually assured destruction don't exist in Martin's world. As the only one with dragons, Daenerys sacks cities and instills terror in her adversaries. Her ancestor, Aegon the Conqueror, was sole possessor of dragons when his invasion targeted a massive stone stronghold; its castle walls melted under intense dragonfire and they now exist under a cursed legacy, like the firestorms that razed Hiroshima and Nagasaki. Those cities largely recovered, but the legacy of radiation illnesses and cancer lingers to this day.

Optimists who welcome nuclear weapons as a stabilizing influence insist that by their very nature, these arms cause rational leaders of stable regimes to maintain strict control over their state's arsenals and moderate their behavior—or risk retaliation. That prompts the question: What happens when nuclear weapons are in the hands of irrational leaders, less than stable countries, or non-state actors? Fortunately for Westeros, its "Mad King" had no dragons at his disposal. "Burn them all," he snarled while ordering his city be set ablaze rather than surrender—showing how retaliatory threats mean little to someone bent on suicidal violence.

Limits of dragon warfare

Nuclear weapons may help prevent existential threats, but they have limited use in other military operations or foreign policy goals. As the Tywin Lannister character mused, a "dragon hasn't won a war in 300 years. Armies win them all the time."

Even with his dragon triumvirate, Aegon the Conqueror was unable to force a resistant kingdom to bended knee. Most of Thrones' fictional realms offer a "target rich" environment, with sizable populations living in castles and pursuing strategies suitable to set-piece battle on open fields. The kingdom of Dorne, however, consisted of a rocky, mountainous, arid, desert landscape with relatively small cities, dispersed populations, and ample hiding places—making it more resistant to dragon warfare. After protracted war, Aegon cut his losses because his armies were repeatedly ambushed by resistance fighters who kept retreating to the hinterlands before dragons could arrive. Peace was only achieved through diplomacy a century later, and the region preserved a wider degree of traditions and freedoms than the rest of the Seven Kingdoms where most of the series takes place.

In similar fashion, during the Vietnam War, the US military faced a protracted campaign by guerrillas undeterred by America's nuclear stockpile. A secret 1967 report produced by the JASON Group determined that nuclear weapons would offer no decisive military advantage. Vietnam was "target poor" with diffuse supply lines and dispersed troops. Our involvement there ended when the Paris Peace Accords declared the "United States and all other countries respect the independence, sovereignty, unity, and territorial integrity of Vietnam."

In much the same way, a Daenerys full of bluster and unwavering confidence takes the ancient city of Meereen by force; none dare openly defy its new queen or else risk a dragon's wrath. As she begins to hold court, however, Daenerys finds political quandaries and challenges where dragons offer little help. Several fans compare Daenerys' struggle to feed her people and end a homegrown insurgency to America's experience in Iraq and the Soviet Union's adventures in Afghanistan. In those theaters, nuclear weapons were ill-suited to achieving specific foreign policy goals. Daenerys ends up relying on her army to conduct counterinsurgency operations and diplomacy to reach an uneasy peace with her neighbors.

If you play with fire…

Nuclear weapons and dragons are dangerous even in times of peace. Summerhall, a ruined castle once used by the Targaryens as a resort home, was the site of a mysterious tragedy paralleling the nuclear bomb's early development. Members of the Targaryen family accidentally unleashed a fiery calamity that killed one of their ancestor kings during an experiment to bring dragons back into their world.

Likewise, a US Atomic Energy Commission report states that there were 26 occurrences of accidental radiation exposures in nuclear experiments and six deaths due to criticality accidents from 1943 to 1970. In 1946, Louis Slotin, a scientist involved in the Manhattan Project, suffered a lethal dose of radiation while calculating the critical mass at which a nuclear chain reaction occurs. The name of the technique used in this procedure: Tickling the Dragon's Tail.

Daenerys' dragons are quite popular with fans of the books and TV series. If they appreciate the strong anti-war themes embraced by Game of Thrones, they may choose to pity her dilemma rather than lust after her offspring. Martin has said his stories try to bear witness to not just the glory of war, but the ugly consequences of violence—on enemies, on innocent bystanders, and, ultimately, on oneself. Given this perspective and the nuclear parallels, her dragons emerge as a more nuanced plot device; rather than simply "cool" (or hot) creatures, they're complex creatures that may threaten a character or the population as a whole. When the books and shows are finished, it would not be surprising for Daenerys' dragons to meet a tragic end, like so many beloved characters in the series; the dragons could turn on their masters, Daenerys might sacrifice them in the name of peace, or the dragons could unleash unintended desolation across Westeros.