system
Given the following post, respond as if you're commenting on Reddit:
human
[Half Life] Why didn't the combine eliminate all the humans after they won the 7 hour war?

I always wondered why the combine keep Dr. Breen and a small pocket of humanity alive. They clearly pose a threat and have formed a resistance. 

Are they similar to the Borg in that they need other organisms?
gpt
All human life will die... once the Combine is done with them. It boils down to 2 stages. In the first stage, humanity is used as a brute labor force to assist in the looting of Earth. In the second, humans are used as the base stock for a new slave caste, modified to suit the Combine's purposes. When everything worth taking is gone, what remains of unmodified humanity will be left behind in the husk that was Earth to await extinction. Nothing that we today would identify as human would last much longer.

When Half Life 2 starts, the transition between phases has already begun. If left to their own devices a while longer, the Combine would have driven humanity extinct in just a few more years.