diplomacy vs dialogue

diplomacy and dialogue both are nouns.

Word	Noun	Adjective	Verb	Adverb
diplomacy	Yes	No	No	No
dialogue	Yes	No	No	No

As nouns, dialogue is a hypernym of diplomacy; that is, dialogue is a word with a broader meaning than diplomacy:

Other hypernyms of diplomacy include negotiation, talks.

diplomacy (noun)	dialogue (noun)
subtly skillful handling of a situation	the lines spoken by characters in drama or fiction
wisdom in the management of public affairs	a conversation between two persons
negotiation between nations	a literary composition in the form of a conversation between two people
	a discussion intended to produce an agreement