In 1798, the economist Thomas Malthus outlined his theory that the Earth's capacity to support humans will not be enough to match exponential population growth. Thankfully, he has been proven largely wrong. The number of people on the planet when he was writing stood at 800 million. If his observations were right, we would never have reached today's number of almost eight billion. But the warning is still relevant, particularly as we enter an age of unprecedented environmental instability. Few threats are more pressing than global water supply. The UN estimates that by 2025, 1.8 billion people will be living in regions with absolute water scarcity, defined as the inability to meet demand after all attempts at preservation have been implemented. Today, the Middle East is among the earliest regions hit by the crisis. Most countries in the region are still managing to keep the taps on, but some are already being devastated. After a drought that started in March, Iran is now seeing deadly protests in Khuzestan province. Rights group Amnesty International say that at least eight protesters and bystanders have been killed. And on Friday, Unicef, the UN agency for children, announced that four million people in Lebanon are at risk of losing access to safe water. A quarter of those in jeopardy are refugees. The Middle East is also going to have to deal with scarcity as a geopolitical issue. The dispute between Ethiopia and Sudan and Egypt over Addis Ababa's plan to build a massive dam on the Nile is an example of the complex diplomatic balances that will have to be struck between countries exercising a sovereign right to manage water supplies, against the rights of neighbouring states to not have theirs threatened. Our region has known about this natural threat for years. But countries such as Iran and Lebanon are faring so much worse because of a non-environmental cause: bad governance. Iran has built 600 dams since the revolution, causing huge evaporation waste rates from reservoirs. Lebanon's preventable economic crisis, fuelled by political corruption and inaction, has pushed its water infrastructure to the brink. Others are coping because governments have bought valuable time by preparing for a more vulnerable future. At first glance, the deserts of the Gulf would appear to be a more likely victim of shortages than a once fertile, agrarian state such as Lebanon. And while challenges do exist, the Gulf region's earlier acceptance of the need to manage supplies and prepare has allowed it to support a massive, decades-long increase in its population, while avoiding the terrible disruption seen today elsewhere. There is still hope for countries that have not planned sufficiently to avoid a Malthusian reality, but governments will need to recognise mistakes, act quickly and make amends for their part in fuelling this premature crisis.