Why Did the US Stockpile Chemical Bombs at a Remote Airbase in India?
During WWII, Shamshernagar was one of several US airbases in the extreme eastern part of British-ruled India. Those who know it all, think of Shamshernagar as a cargo hub—a remote place where supplies could be transferred from the Bengal and Assam Railroad onto C-47 and C-46 planes for dangerous flights “Over the Hump” of the Himalayan Mountains to China.
Why then, was Shamshernagar designed as a bomber base, complete with bomb storage facilities and a satellite airfield designed for fighter planes? Why too did Shamshernagar have an “Advance Chemical Park” and a large stockpile of 1000-pound chemical bombs? Long-secret documents in the US National Archives provide some answers, but mysteries remain.
Most American histories of WWII focus on the European and Pacific Theaters, neglecting the enormous importance of events in Asia itself. From Japan’s perspective, the essential goal of the war was to establish permanent control of resources it lacked, particularly oil from the Dutch East Indies and iron, coal and food from China. Indeed, Japan had been waging a brutal war of occupation in China since 1931, a war that included Japanese use of chemical weapons. When they launched new attacks in December 1941, the Japanese intended to seize and hold British-controlled Singapore and Burma, with the added benefit of blocking supplies for China that were flowing along the “Burma Road.” Important though it was, the bombing of Pearl Harbor was not the main event of that month. At Pearl Harbor, the Japanese were trying to forestall likely American intervention, not to seize territory.
From the American perspective, China was essential to the overall war because it kept a substantial portion of the Japanese Army occupied and unavailable to fight elsewhere. The war didn’t have to be won in China but fighting there had to continue. The cost to China of this ongoing war was enormous, with 15 million Chinese lives lost. China’s losses were second only to the 20 million Soviet lives lost, vastly exceeding the US total of 420,000 fatalities.
Specific planning for Shamshernagar Airfield began in August of 1943. At that time some supplies were being flown from Allied airbases near Dinjin in far northeastern India to Kunming, China. Work had begun a few months earlier to build a road from Lido to Kunming, although the first truck convoys would not reach China until January of 1945. The tenuous air route from Dinjin to Kunming managed to thread a needle between the impossible highest ranges of the Himalayas to the north and Japanese-occupied parts of Burma to the south. The route was possible—but just barely so—for unarmed and unpressurized C-46 and C-47 planes flying in very dangerous terrain and horrible weather.
The Allies needed a less demanding air route. They also needed to deal with the very real threat posed by Japanese fighter planes based at Myitkyina, Burma. The situation became even more dangerous in March 1944 when Japanese ground forces (aided by the pro-independence Indian National Army) moved into India itself and besieged the British and Indian forces at Imphal. During late 1943 and early 1944, The Ally’s need for bases in the area of Shamshernagar was rightly focused on the need for bombers and fighters. Not until the Allies recaptured Myitkyina in June 1944 could Shamshernagar be used as a key point of origin for the “Oboe” air route that crossed lower heights of the Himalayas.
It made perfect sense to equip Shamshernagar with bomb storage areas and to build a nearby satellite base for fighter planes. A mystery remains, however, as to why the US continued as late as May 1945 to build specialized storage facilities for toxic chemical bombs and to stockpile 1000-pound, M79 bombs filled with highly poisonous cyanogen chloride. A few months earlier, these bombs might have been destined for transport Over the Hump for use in Operation Matterhorn. Matterhorn raids by B-29s were launched from bases near Chengdu, China and marked the first time since the Doolittle Raid that the US bombed the Japanese mainland. By May 1945, however, the US had established better B-29 bases in the Marianas, and the last of the B-29s had moved there. Perhaps instead the chemical bombs at Shamshernagar were considered a necessary option for “retaliation in kind” if the Japanese used chemical weapons in China or Southeast Asia. A major Allied offensive to retake Singapore was planned for late 1945, and soldiers in the US Chemical Warfare Service had long been told their weapons were most likely to be used late in the war as the Axis forces tried desperately to avoid defeat. Perhaps war-weary Americans even wanted the option of initiating chemical bombing as an alternative to land invasions of Japan and Singapore.
Fortunately, the war ended in August 1945, without an offensive to retake Singapore, without an invasion of Japan and without Allied use of toxic chemical weapons. The chemical bombs at Shamshernagar were shipped back to the central chemical weapons depot at Ondal. My father was one of the enlisted men who helped dump these and many thousands of other unused chemical bombs into the Bay of Bengal.
Original documents about Shamshernagar Airfield have been stored in rarely opened boxes at the US National Archives for a very long time. Hoosier Scientist has now posted them alongside other information about US chemical weapons in the China-Burma-India Theater during WWII. We invite you to form your own opinions about the US intent, the full history of events and the range of possible alternative outcomes. Other resource links are available here.