What I don't understand is why go to Mars at all, when all that the people here on Earth have to do is to have less children, so that there are enough resources left for everyone.

As people die naturally, without war, so the population will reduce; and if modern people limit themselves to having one child, or remaining childless, like so many do these days, then there will be a natural reduction in population without resorting to war.

It is only where people have more than one child where the population continues to increase, and when they have floods of children that the population increases exponentially.

This must surely be a foolish thing to do when it leads to war.

"Homo Sapiens" is not as wise as they might care to think they are.

Which is why some choose to remain celibate.

This does NOT prevent you from loving other people.