Much of Japan’s economy was bolstered by sales of a single commodity – silk. From the 1890s, when the US overtook France as the main export market, a huge proportion of Japan’s foreign currency earnings derived from the export of raw silk and related products to the United States. Fully 10% of Japan’s arable land was taken up with mulberry orchards to feed silk worms, while by 1929, the United States accounted for 95% of Japan’s silk trade, and the silk trade accounted for up to 54% of all Japan’s exports. The introduction of Coco Chanel’s “Little Black Dress” in 1926 was not merely a revolution in fashion, but in international commerce, delivering a sharp blow to Japan’s export prospects, which had previously relied on intricate and bulky gowns. So, too, was the widening availability of rayon, an artificial fibre perfected in 1924 and soon undercutting silk on the market. The onset of a global depression, which impacted the United States in 1929, had a predictable effect on the sales of luxury items, including silk clothing, causing Japan’s silk exports to the US to plummet during the 1930s to a mere eighth of their former level. Only the rise of the silk stocking, a mass-production item after the invention of all-in-one knitting machine, offered any respite to Japan’s troubled export market.

While the battles of Kalkhin Gol were still raging in 1939, a far quieter, but arguably even more destructive blow was struck against Japan in New York, where the new wonder-fiber nylon was unveiled at the World’s Fair. Nylon would soon be offering a cheap alternative to silk stockings, which, in the decades since women’s dresses began to use less material and ruffles, had become the main use for Japanese silk. The arrival of nylon spelled disaster for Japan’s own industrial calculations, suggesting that the silk-stocking industry, Japan’s last big source of export revenue, was about to take a tumble. Without the $100 million per year that Japan earned from silk exports to the United States, the nation would have to rely solely on its dwindling gold reserves, and whatever revenue it could scrape from the drugs levies of Manchukuo.

How much longer could Japan afford to fight its China war? US analysts believed that Japan might still have enough gold reserves to push on for another two years. After that, it was confidently predicted, Japan would be out of money, and out of time… sometime in the autumn of 1941.

But the US was also heavily reliant on the Japanese for certain commodities – silk, for example, was not simply a luxury item, but also a crucial component in the manufacture of American parachutes. With China in a state of crisis, the best sources for it were Japan and Manchukuo! Fortunately for the US, there was enough raw silk stockpiled in the US already to adequately equip 200,000 parachutists, although there were still concerns that the US might run short of the coarse spun silk required in munitions’ igniter cloth and lacing for artillery. Already in 1940, the supply of waste silk from Japan had become suspiciously thin – it was believed that the Japanese were stockpiling their own silk. The most crucial of the US needs for silk was for use in naval cartridge cloth – the material used in powder bags for large-calibre ships’ guns. This need was met by massive purchases from China, often of the off-cuts from Japanese-owned mills.

An extract from Japan at War in the Pacific: The Rise and Fall of the Japanese Empire in Asia (1868-1945) by Jonathan Clements.