Sentence:  This would be by far the better choice , when `` it is a question of <WSD>allowing</WSD> the human race to survive , possibly under the domination of a regime which most of us detest , or of allowing it to destroy itself in appalling and prolonged anguish '' . 
Meaning of the word marked with <WSD> tags:  make it possible through a specific action or lack of action for something to happen