COERCIVE DIPLOMACY? What the heck is that? How is threatening anything diplomatic?

Maybe they meant cofeveve diplomacy!

from Wikipedia
Coercive diplomacy or "forceful persuasion" is the "attempt to get a target, a state, a group (or groups) within a state, or a nonstate actor-to change its objectionable behavior through either the threat to use force or the actual use of limited force." This term also refers to "diplomacy presupposing the use or threatened use of military force to achieve political objectives."

its not