The conclusion of the argument is that to maintain military deterrence, a nation should be believed to have retaliatory power so that a potential aggressor nation would have reason to think that it would not be able to defend itself against such retaliation.
Why? The theory behind military deterrence is based on the psychological truth that the fear of retaliation makes a would-be aggressor hesitate before attacking. The argument states that sometimes this is even sufficient to deter an attack altogether.
NOTE: This does not mean that you can write out that last sentence as a conditional sentence. The word "often" takes away the possibility of writing it out as a Sufficient & Necessary condition.
This is a Must Be True question. Thus, our correct answer must be 100% supported by the passage.
Answer choice (C) states: "One nation's failing to attack another establishes that the nation that fails to attack believes that it could not withstand a retaliatory attack from the other nation."
We are told that sometimes the fear of retaliation is sufficient to make a would-be aggressor not attack. However, this does not mean that if they do not attack, it is because they fear retaliation. There could be hundreds of reasons why a country fails to attack another. Just because a country does not attack another country does not necessarily establish that it would not withstand a retaliatory attack from the other nation. It could just mean that the two countries are at peace.
All we know from the stimulus is that often the fear of retaliation deters potential aggressors from attacking since they may have reason to think that they would not be able to defend themselves against retaliation.
Hope that clears things up! Please let us know if you have any other questions.
