Parallel idea

[alexhartmann_316]

Hello, everybody.

My name is Alexandre, and it is a pleasure to join you.

I have read in a text: "The UN was founded and grew to prominence in the era of the Cold War, when much of diplomacy was devoted to dealing with threats arising from external aggression."
Based on this sentence, can one state: "When the UN began its activities, its sole concern had to do with dealing with issues concerning the Cold War?"
I think the first sentence leads to say that the statement is correct, though in the answer sheet it is incorrect.

It is a case of parallelism. In the sentence "The UN was founded in the era of the Cold War, and the UN grew to prominence in the era of the Cold War," the coordinating conjunction pairs 'was founded' and 'grew to prominence' and joins both to the subject 'The UN' and to the adverb phrase 'in the era of the Cold War'.
"The UN was founded in 1945, and it grew to prominence in the era of the Cold War" is a clear sentence that could substitute for the awkward previous sentence.
Could you help me with this?

[Tdol]

much of- this does not equal 'sole concern'.