。
There is no one who doesn't wish for peace.
Literal
Peace [object-を] wish-not person [topic-は] not-exist.
Double negation creating a strong positive: 望まない人はいない = 'there is no one who does not wish' = 'everyone wishes.' This rhetorical move (negative + negative = emphatic affirmative) is common in formal Japanese rhetoric, especially around abstract values like peace, freedom, or justice. 人 here could also be replaced by もの ('one') in literary register without changing the meaning.