defense vs justification

defense and justification both are nouns.

Word	Noun	Adjective	Verb	Adverb
defense	Yes	No	No	No
justification	Yes	No	No	No

As nouns, justification is a hypernym of defense; that is, justification is a word with a broader meaning than defense:

defense (noun)	justification (noun)
(military) military action or resources protecting a country against potential enemies	the act of defending or explaining or making excuses for by reasoning
the act of defending someone or something against attack or injury	something (such as a fact or circumstance) that shows an action to be reasonable or necessary
a defendant's answer or plea denying the truth of the charges against him	a statement in explanation of some action or belief
protection from harm
a structure used to defend against attack
the justification for some act or belief
the speech act of answering an attack on your assertions
the defendant and his legal advisors collectively
(sports) the team that is trying to prevent the other team from scoring
an organization of defenders that provides resistance against attack
(psychiatry) an unconscious process that tries to reduce the anxiety associated with instinctive desires