AP style: 'Justify'
AP has issued one of its periodic style updates, and one might be of interest to usage mavens:
Justify: Smith justified his actions means Smith demonstrated that his actions were right. If the actions are still controversial, say Smith sought to justify his actions.
It's much like refute (proved) and rebut (sought to prove). I like it, but as with all usage issues, AP is splitting hairs a tad. For instance, Merriam-Webster's entry first lists to provide or be a good reason for (something) : to prove or show (something) to be just, right, or reasonable, to provide a good reason for the actions of (someone).
To "provide" is a tad less than the AP's take, which would fall more under "prove."
AP is in more line with its master dictionary, Webster's New World 5th: to show to be just, right, or in accord with reason; vindicate.
American Heritage is similar : To demonstrate or prove to be just, right, or valid.
M-W is always considered the more liberal. And in the digital age you've got to deal with the reality that many people are going to get their usage sense from places like Your Dictionary.com (The definition of justify is to provide an explanation or rationale for something to make it seem OK or to prove it is correct or OK.) or Dictionary.com ( well-grounded), both of which are less restrictive.
So be aware.