Which term identifies the underlined sentence in the outline? concluding statement thesis statement topic sentence supporting detail

I dont quite understand this question. can you pls explain and i will edit my answer

answer: ensure protection from communism

explanation:

the north atlantic treaty was largely dormant until the korean war initiated the establishment of nato to implement it, by means of an integrated military structure: this included the formation of supreme headquarters allied powers europe in 1951, which adopted the western union's military structures and plans.