This cloze test question requires selecting the word that correctly fills gap 7. The passage discusses the United Nations Security Council and its responsibilities. The standard phrase used in the UN Charter to describe the Council's core mandate is the maintenance of international peace and security.
The correct word is peace. "International peace and security" is a fixed collocation drawn directly from Article 1 of the UN Charter, which states that one of the purposes of the United Nations is to maintain international peace and security. The subsequent gap (gap 8) is filled by "security" to complete this well-known phrase.
The other options do not form the correct collocation:
"International relation" (singular) is grammatically awkward and not the standard phrase.
"International affairs" is a valid collocation in general English but does not match the specific UN Charter language about the Security Council's mandate.
"International relationship" is not the standard diplomatic or legal term used in this context.