Without water, no human being or animal can live, no food can be produced.
Water is also irreplaceable by other substances.
Unlike oil or other strategic resources, it cannot be substituted by anything else. But freshwater is getting scarce. At least 130 million people in 80 countries already suffer from acute water shortage. Their number will rise to one billion by the year 2025. Water distribution is also very unequal, both within countries and among different states.