Your enemy has you over a barrel. What do you do? You put HIM over one...that doesn't actually exist.
Do We Have This One?? I've looked and looked and can only find the narrowly specific tropes mentioned as possible subtropes, but not the overall concept (which would catch things that don't fit the existing two, such as the Evil, Inc example that sparked off the whole search for this).
Formerly: Corbomite Maneuver, Badass Bluff It's bad times for Our Heroes: the Bad Guy has leverage over them and isn't afraid to use it. Whether he has a bigger gun or blackmail information, there's no last-minute plan that is going to save our heroes now... But wait! The Hero is telling the Big Bad that things aren't as they seem - it's the bad guy who's in trouble. Because the Good Guys have something that they aren't afraid to use to foil his evil scheme. Don't believe it? Are we bluffing? Maybe, but can you, Mr. Big Bad, take the risk that we're not... The Big Bad is forced to concede that he does not want to take that risk. And so Our Heroes have won the day...through the use of the Corbomite Maneuver. A bluff...of grand proportions. Telling the enemy that if he proceeds with his scheme, things will go Very Badly Indeed for him, so perhaps he should reconsider his evil plans. When, in fact, there is no such Phlebotinum, no such plan, no such magic doodad. But the enemy doesn't know that. And so Our Heroes win. The Corbomite Maneuver may consist of a Backup Bluff, and sometimes involves scamming Cthulhu. Weapons for Intimidation may also be involved, but are by no means required.