View with binoculars from Dora Observatory at South Korea and North Korea border, March 24, 2017. (Credit: Panu Kosonen via Shutterstock)

Live anthrax spores were mistakenly shipped from the U.S. to Osan Air Force Base in South Korea in May 2015. Just 10 days later, North Korean leader Kim Jong Un toured the Pyongyang Bio-technical Institute. The televised footage showed American and South Korean experts that the equipment at the facility was potentially “dual use”—it not only had capacity to enhance agricultural productivity, but also could produce military-size batches of anthrax for weaponized use.

North Korea was signaling that it too has biological weapons—and is ready to use them, some experts contend.

The hermit kingdom, currently engaged in a kind of nuclear standoff with the international community, has also held onto its biological weapons capacities—and could weaponize germs such as anthrax and smallpox just days into a military conflict, according to a new report published by experts at the Belfer Center for Science and International Affairs at Harvard University.

“North Korea’s Biological Weapons Program: The Known and Unknown” concludes there could be as many as 13 biological agents cultivated by the Democratic People’s Republic of Korea—and it could be delivered on missiles, by drone, or even through human agents with backpack sprayers and/or directly into water supplies.

But more information needs to be collected by intelligence agencies, whose attention has been focused on the DPRK’s nuclear capabilities and threats, they add.

“Although the lack of recent and reliable public information prevents a comprehensive assessment of its current capability, threats posed by North Korea’s biological weapons program must be considered a realistic proposition and addressed by the international community,” they write.

The history of biological weapons on the peninsula extends back to the conflict that never officially ended, the Korean War. China and the DPRK accused the U.S. of using biological weapons during the war, blaming American forces for outbreaks of cholera, typhus, typhoid and smallpox. Defectors from the North have now said that the DPRK started developing its own biological weapons as early as the 1960s in response to those claims.

At the turn of the 21st century, South Korean intelligence agencies claimed that North Korea had 13 pathogens on which it was basing its weapons program: anthrax, botulism, cholera, Korean hemorrhagic fever, plague, smallpox, typhoid fever, yellow fever, dysentery, brucellosis, staph bacteria, typhus fever and alimentary toxic aleukia.

“North Korea is assumed to have 13 types of biological agents including anthrax and the plague, and it is possible that it would use them in bioterrorism or in an all-out war,” the U.S. and the Republic of Korea said in a joint press conference in 2015.

Indeed, the U.S. and South Korea have been preparing for North Korea’s BW capabilities for more than a decade. American troops stationed in Korea have been vaccinated against smallpox and anthrax since 2004, and the two countries’ military exercises have included joint training on bio-defense since 2011, according to the report. At the beginning of this year, the two allies deployed advanced detection equipment in the important port of Busan as part of the Joint United States Forces Korea portal and Integrated Threat Recognition (JUPITR) program, it adds.

But recent developments have heightened concerns. Kim Jong Un’s recent pronouncements on developing agriculture could have a double meaning—those facilities for “Juche fertilizer” could instead be focused on stockpiling deadly agents in case of conflict with Western forces. Indeed, the international community may have assisted the DPRK’s weapons program unwittingly. An international farming nonprofit known as the Center for Agriculture and Biosciences International established a facility in North Korea to produce Bacillus thuringiensis (Bt) as a bio-pesticide in the country. But Bt is a close relative to anthrax—and that knowledge could already be put to use for the country’s BW program.

Human vectors could be the plan, the report adds.

“It is theoretically possible that North Korean sleeper agents disguised as cleaning and disinfection personnel could disperse BW agents with backpack sprayers,” they write. “Another possibility is that North Korean agents will introduce BW into water supplies for major metropolitan areas.”

The Pyongyang Bio-technical Institute which the DPRK leader touted in 2015 was likely the source of the VX nerve agent which two assassins used to kill his half-brother Kim Jong Nam earlier this year in a Malaysian airport, according to the report.