counterstrike vs counterattack

counterstrike is not a noun while counterattack is a noun.

Word	Noun	Adjective	Verb	Adverb
counterstrike	No	No	Yes	No
counterattack	Yes	No	Yes	No

As verbs, counterstrike and counterattack are synonyms defined as:

counterstrike (noun)	counterattack (noun)
	an attack by a defending force against an attacking enemy force in order to regain lost ground or cut off enemy advance units etc.
	(chess) an attack that is intended to counter the opponent's advantage in another part of the board

counterstrike (verb)	counterattack (verb)
make a counterattack	make a counterattack