qui vive vs air alert

qui vive and air alert both are nouns.

Word	Noun	Adjective	Verb	Adverb
qui vive	Yes	No	No	No
air alert	Yes	No	No	No

As nouns, air alert is a hyponym of qui vive; that is, air alert is a word with a more specific, narrower meaning than qui vive:

qui vive: condition of heightened watchfulness or preparation for action
air alert: the condition in which combat aircraft are airborne and ready for an operation

Other hyponyms of qui vive include red alert, strip alert.

qui vive (noun)	air alert (noun)
condition of heightened watchfulness or preparation for action	the warning signal that begins a period of preparation for an enemy air attack
	the condition in which combat aircraft are airborne and ready for an operation
	the time period during which military and civilian agencies are prepared for an enemy air attack