What's a resource scarcity that could trigger a world war?

It is said that the third world war will be fought over the water. It is likely to be true because a human being can adopt an alternative of any other resource, but there is no alternative for water. For example, oil can be replaced with electricity and hydrogen for automobiles, the use of fossil fuel can be replaced with renewable energy like solar energy for producing electricity, but there is no alternative for water. According to the estimates by the World Health Organization, around 2.1 billion people lack clean drinking water at their premises. The concern around the depletion of groundwater and plastic waste in the ocean is multiplying the problem of water crisis day by day.

Urgent actions are needed to fight the challenge posed by the water crisis. Otherwise, the situation will worsen to the extent that it may lead to the third world war in future years.