World War I is sometimes referred as the “chemist’s war” due to the prevalence of poison gas warfare, including the use of massive amounts of nitrogen. It proved to be the beginning of a fundamental change in the world’s ecological relation with nitrogen, according to Gregory Cushman, Associate Professor for history at the University of Kansas, states in his fascinating book “Guano and the Opening of the Pacific World.” This is the result of the development of the Haber-Bosch process, a process that uses the reaction of hydrogen and nitrogen to produce ammonia, by German chemists in 1909. This process was meant to feed the world’s hunger for fertilizers, but with the outbreak of the war, it became an indispensable resource. This invention therefore helped the Germans to supply the most crucial things for the war effort: food and munitions. Food security is one of the key tasks of a nation to secure social peace, especially in wartime because soldiers and civilians have to be provided with adequate aliment for victory. Historically, there have been numerous riots and revolutions resulting from (among other reasons) periods of starvation due to bad harvests, such as the revolution of 1848 after the “hungry 40s” or the French revolution. In 1798 the British economist Thomas Malthus published his “Essay on the Principles of Population”, in which he argued in favor of controlling mechanisms of population growth. In his opinion, population, when unchecked growing, increases in geometrical ratio and food supply increases only arithmetically, which will result in a collapse of the food supply. However, he did not expect the food production to increase as rapidly as it has over the last two centuries due to technological and scientific advancement in the field of fertilizers and other agricultural techniques. In the 19th century, global population grew from 1 to 1.6 billion – mostly in Europe – and bird excrement helped feed the increased population. In most parts of Europe, the disposable arable land was already cultivated, which meant that they could not simply expand the cultivated land to meet the needs of a growing population, but had to increase the yields of the present fields. When removing the yield, the natural circle and production of essential nutrients is disturbed, and therefore, they had to be added artificially. In the early pre-industrial days, manure was applied; later, better alternatives were found in guano and salitre. Guano is nitrogen-rich, solidified bird excrement that can only be found in coastal, rainless regions, and the richest deposits in terms of nitrogen content were found on the Peruvian coast. The nutrient there had been used for centuries by local agriculture, but was not brought to Europe until 1804 by Alexander von Humboldt. The second form of natural sources of nitrogen was salitre, the Spanish name for sodium nitrate, also called Chile or Peru Saltpeter (not to be confused with ordinary Saltpeter). It is one of the few naturally bound forms of nitrogen in the earth crust and was discovered in the Atacama Desert. Salitre can not only be used as a fertilizer, but also to produce gunpowder. For example, by 1900 the US was already using it for as much as 50 percent of its imports for this purpose. The invalidity Malthusian economics is the fundamental basis for the argument that the world cannot run out of resources, because human beings are resourceful in finding alternatives when prices rise in times of scarcity. This model was best contradicted by the result of the guano mania of the 19th century, according to geologist Michael S. Fulp in his article in the Mercenary Geologist. He states that guano was the only mineral resource the world has ever run out of. This statement and the theory of inexhaustible resources can be debated, as for the case of guano, huge amounts were exported from Peru and the islands in the Pacific and the most suitable spots were mined out by 1874. This was not a major problem for Europe, as the exports of salitre could largely satiate European farmer’s hunger for nitrogen, but local farmers that had been using the nutrients for centuries were left with empty deposits. The discovery of these two forms of fixed nitrogen, serving as fertilizers, led to first imperialistic tendencies of the US concerning its “backyard” Latin America. It also led to a war, which was the beginning of the longest lasting diplomatic stalemate in Latin America. In 1856 the USA adopted the “Guano Island Act”, which enabled the seizing by US citizens of any inhabited island where guano is found. Gregory Cushman calls the claims under this act a “landmark in the history of US imperialism”. Under this act, 66 islands were claimed, nine of which remain US territory today. The most important turning-point in the geo-political distribution of guano and salitre exports was probably the “War of the Pacific” of Chile against Peru and Bolivia, which lasted from 1879 till 1884. This led to Chile’s acquisition of the salitre-rich regions of Tarapacá (formerly Peruvian) and Antofagasta (formerly Bolivian coastal region). In this war – Salpeterkrieg, in German – Bolivia lost its access to the sea and Peru lost one of its most important sources of income in the form of salitre exports. However, the real winner was Britain, speculating on a Chilean victory and afterwards, pocketing large shares of the salitre incomes. Another result of the war was the broken diplomatic ties between Chile and Bolivia during most of the 20th century. The final step of which was Chile’s case against Bolivia before the International Court of Justice in 2013 regarding its access to the sea set down in the peace treaty of 1904 which was, as Gideon Long of the BBC calls it, “Latin America’s longest-running and bitterest diplomatic stand-offs.” The prosperity of the salitre industry did not last long though, because European scientists were searching for alternatives to the expensive and uncertain source of natural nitrates. For example, Justus von Liebig (1803-73) found “fossil guano” (bones and teeth of extinct reptiles) as a substitute. Due to the limited disposability of this resource, it was never applied in a broad way and could not replace Latin American imports. However, the breakthrough was then the invention by Fritz Haber and Carl Bosch developing the synthesis of ammonia from atmospheric nitrogen. The first plant in Oppau, Germany producing in a larger scale started in 1913 by BASF, a chemical manufacturer. When the situation became critical in Germany due to the British sea blockade starting with the outbreak of the war in summer of 1914, cutting off nitrogen imports from Latin America, this scientific breakthrough came right in time. This recently inaugurated ammonia production process was consequently used to produce for the German war industry. The Haber-Bosch Proces is therefore another example of a harmless invention, later used for belligerent actions, but also signified the one of the most crucial inventions of our time. It freed European farmer’s from the dependence on natural sources and marks a prerequisite for the population growth throughout the 20th and 21st century. On the other side the mining of atmospheric nitrogen led to an increase of reactive nitrogen entering the earth’s biogeochemical system by approximately 150%, compared to pre-industrial times acording to a report „Green Economy in a Blue World“ of UNEP, FAO and other international organizations. This leads to increasing problems in water quality and marine life. The history of nitrogen use shows how the need for resources can have violent conflicts as a consequence which may remain for a very long time in the collective memory of the respective nations, but also how scarcity and uncertain resource supply may trigger scientific development and the search for alternatives.