The pressure on natural resources is intense. Much of the world's forest has been destroyed, and most people can no longer rely on fuelwood for energy. The catch of fish from the sea has peaked. The planet is undergoing the sixth mass planetary extinction of species, this one entirely because of mankind's large numbers and industrial activity. The planet's environment and diversity will be destroyed unless human population and industrial activity are reduced dramatically and immediately.
War is justified as defending or promoting the lives or condition of a country's citizens.
The world political and economic system is committed to world peace and increased industrial production. Every year that passes without a global war means that when it finally occurs, it will be even more massive in size and more nearly complete in its destruction. The destruction of the planet's environment and biodiversity may coincidentally be halted by global war, but saving biodiversity or the environment will not be the cause of global war. The large human population has been made possible because of access to fossil fuel. Industrial development has sewn the seeds of its own destruction.