At the beginning of the third paragraph, the author refers to “those who believe that peace will not be attained until some super-tribunal is established” primarily to

C. highlight a potential drawback of a recommendation

Explanation:

The text in quote is from the acceptance speech of Frank B. Kellogg when he was awarded the Nobel Peace Prize in 1930 for his work in establishing the Kellogg–Briand Pact which when signed, was a promise by the country which signed to avoid using war to settle disputes.

When in the third paragraph he spoke of those who believed a super tribunal was necessary to enforce peace, he was highlighting a drawback to the recommendations in the treaty because if no super tribunal was around to enforce the treaty, it is reasonable to believe that some will violate it.