The active ingredient of war

One of the forgotten battles of the first world war was fought for Chilean dirt. It wasn't just any dirt, though – it was caliche, a whitish substance rich in the crucial mineral sodium nitrate. Nitrates are the active ingredient of bombs and bullets, and they became the conflict mineral of the Great War. Without a ready supply of Chilean dirt, the allies would have very likely lost the war.

When we imagine the first world war, we tend to think of the endless nights in muddy trenches, or the vast battlegrounds on which machine guns and artillery barrages decimated a generation. We don't usually think of the men and machines that were chipping away at the Atacama Desert to feed a far-off war. As we approach the centenary of the first world war, however, we should remember not just the battlefields of Europe, but also the distant nitrate fields that enabled one of the most destructive conflicts in history.

Nitrates are a stable and usable form of the nitrogen found in our atmosphere, and they feed two of mankind's oldest activities: agriculture and war. If you mix nitrates, potash, and phosphoric acid into soil, crops grow with a new vitality. If you mix them with charcoal and sulfur, the result is explosive black powder. Nitrates dissolve easily, however, and almost never accumulate in nature. Back in the 1830s, desert nitrates still competed with nitrate-rich guano deposits, but as guano supplies dwindled, the South American desert became the world's last remaining viable source. A swelling stream of miners in search of “white gold” began to settle the desert.



The first fight for caliche

For most of the 19th century, Chile shared the nitrate fields with Bolivia and Peru. In 1874, however, Chilean businesses expanded mining in what was then Bolivia, and the two countries struck a deal: Chile would cancel a debt owed by Bolivia, and Bolivia wouldn't tax Chile for exports. A few years later, Bolivia established an export tax nonetheless, and Chilean companies refused to pay. Bolivia seized the companies, Chile intervened, and soon Bolivia and its ally Peru were at war with Chile. The war of the Pacific lasted five bloody years. When the peace treaty was finally signed, Chile had expanded its borders to include the vast wealth of the desert.

They'd gone to war over one of the most inhospitable places on Earth. In 1913, a year before the Great War began, an American geologist wrote:

In crossing this region one cannot help feeling the utter helplessness of man in the face of such great expanses of waterless and lifeless wastes … One fails at first to understand how men are willing to live there year after year.

But this was the power of caliche. Each day, miners labored through intense heat to carve holes with crowbars in the hard sand. If they found caliche, they ignited black powder to fracture the desert's surface. As a British-Irish journalist wrote in 1890, the air then “filled with saline particles, and with a fine dust which settled down like a second skin on clothes, face, and hands.” The jagged white chunks they unearthed were sent to processing plants, where they were dissolved and left to crystallize. The resulting nitrates could be made into black powder to break loose more caliche, or they could be shipped out as the raw materials of war.

Gas attack, Loos, France. Another harsh environment.The first world war is sometimes called 'the chemists' war' because of the use of chemical weapons; chemists' roles in explosives and mining were also crucial. Photograph: Print Collector/Getty Images

Explosive exports

Nitrate exports seemed unstoppable. Between 1830 and 1880, they increased from 8,300 to 226,000 tons. A “Nitrate Railway” was built to link mines in the desert to ports on the Pacific. By 1911, Chile was exporting an astounding 2.5m tonnes each year and generating more than half its income from nitrate taxes and land sales. As Europe began to spiral toward war, however, nitrates placed Chile precariously between hostile nations: Britain held 5% of the market, America held 17%, and Germany held 33%.

War broke out in July 1914, and in a testament to its importance, the coast of Chile became one of the earliest sites of naval battle. Germany's Pacific naval fleet steamed to Coronel, where German colonists – many of whom were nitrate merchants – threw a banquet. On 1 November, a smaller British fleet arrived and attacked the German ships. It was badly defeated. (The presence of both fleets violated Chilean sovereignty, but Chile wasn't about to intervene in a global conflict). For the moment, essential nitrate shipments to the allies were blocked.

The British reinforced their fleet in December. The German fleet was protecting commercial interests in the Falkland Islands, and there British attacks proved successful. Allied nitrate shipments resumed, and this time the British blocked German shipments. These were opening salvos in the massive blockades that would define the war. In a global war, commerce becomes just one more battleground: the next year, in 1915, the proportion of German nitrate holdings fell to zero.

This was the extent of actual warfare in Chile, but the allies leveraged their influence in South America. Chile's government was walking the tightrope of neutrality; it stood to gain from wartime demand and competition. The British, however, wanted to eliminate competition and centralise nitrate supplies. In 1916, they blacklisted and then took over the business of German companies. Over the objections of Chileans, the Americans joined in to keep prices low. When a Chilean court ruling demanded that American oil companies respect their contracts with German companies, the US War Trade Board simply cut off oil supplies to the nitrate fields. Chile relented. From that point on, the country continued to profit from nitrate sales, but less as an active producer than as a subject of allied needs.



A new era of warfare

The allies may have had Chile's nitrates at their disposal, but the central powers had chemistry. As many historians have argued, the war dragged on largely because German scientists, particularly Fritz Haber and Carl Bosch, managed to match the Allied supply by synthesising nitrates on an industrial scale. What is still up for debate is whether Germany's losses in Chile were a strategic failure, putting the country at great risk of losing the war, or instead a shrewd calculation based on knowledge of the impending Haber-Bosch process.

Either way, the battle for nitrates reminds us that warfare was entering a new era. From then on, war would be deeply technological and increasingly global – not just in the location of battlefields, but also in the sources of raw materials and the vast impacts of wartime production. The first world war was the last major conflict to rely heavily on natural nitrates. Within a few years, competition from nitrate factories ended the boom in Chile. To this day, huge swaths of Chilean desert are pockmarked with boulders and dotted with the iron remnants of heavy machinery.

There's an odd resemblance between photographs of Chile's nitrate fields and Europe's battlefields. Perhaps this isn't entirely a coincidence. Mining transformed one landscape and war transformed another. Chilean miners were soldiers of a sort, carrying crowbars and black powder instead of rifles and bullets. And the bullets and bombs that exploded in Belgium and Verdun and Cambrai were felt, quite literally, across the world – in each burst of black powder that fractured the desert and kept the weapons coming.

Daniel A Gross is journalist-in-residence at the Max Planck Institute, Berlin. He tweets @readwriteradio

