When I read this article about "Michelle Obama's Friendship Secrets" (blurb: "The First Lady has no use for frenemies...and neither should you") , I was a bit confused. I get the idea that Michelle O makes smart, "adult" relationships with other women...and I get that the author is trying to discourage the perpetuation of women as vicious bitches constantly at war with each other.
This article has nothing whatsoever to do with the word "frenemy".
The frenemy is a very specific type of person in your life. On the surface, everything appears to look like a friendship. You socialize with this person, you invite each other to personal events, you laugh and have fun with the person. But make no mistake: from the very beginning you are competitors at war with each other. It may be only one-sided; one person might not even know the other person is the frenemy [until it is too late]. It's not a war of nuclear explosions as is suggested by the article; it's a war of scorched earth. The frenemy is undermining you either directly (casual little barbs, insults that are "kidding", bad advice, etc) or indirectly via your social circles, to absorb or eradicate your personal and emotional assets. There is no betrayal because an enemy implicitly cannot betray a friendship that doesn't exist.
Also, I call baloney to the statement that Michelle Obama has no frenemies. The U.S. presidency is one of the most highly competitive and sought after political positions in the world. There is no way that one can navigate the political waters with any degree of success and fail to encounter frenemy relationships. I think it would be more correct to say that Mrs. O is savvy enough to correctly identify her frenemies and mitigate her exposure to them.
ruse
noun \ˈrüs, ˈrüz\Definition of RUSE
from http://www.merriam-webster.com/dictionary/ruse