The nation that one day world will run out of the necessities of life was advanced in the late eighteenth century by the English political economist, Thomas Malthus. In an essay on the principle of population, first published in 1798, he hypothesis that human number tend to increase at a geometric rate, while our ability to feed ourselves only increases arithmetically. This, he says, is bound to lead to profound human and economic crises when our numbers outpace our supplies. Malthusian theory has not gone unchallenged in the countries since. Advances in technology, improvements in productivity, and the opening of new agricultural lands have thrown much of what Malthus says into doubt. However his approach to thinking about population and resources has never quite gone away. Over the past 20 years, it has enjoyed something of a comeback among writers concerned with the direction of human development and what they see as a scarcity crisis approaching our civilisation.
This Malthusian turn in IR expresses itself in a series of well-publicised debates on resource scarcity. One of these revolves around the dangers posed by further rises in the world's population. Another looks at how unequal distributions of power and wealth can produce socially-constructed hunger by failing to distribute food to poor parts of the population. A third focuses specifically on water scarcity and fears that shortages will give rise to new conflicts between and within states. Some experts even believe that oil will become increasingly scarce over the next few decades. According to this theory, known as peak oil, the discovery and exploitation of fossil fuel reserves will reach their peak by the middle of the twenty-first century. If and when this occurs, it will likely give rise to intense competition between states seeking access to a resource upon which, at least for the time being, our international economic system depends.