If I force a character away from their goals and objectives to serve the current story's immediate needs, that could very well be a compel.  Or it could just be storytelling.

Of what aspect?  Who really cares.  p.78 one into existence just for this purpose if you have to.  But having a story-level aspect that can easily be used to excuse ninjas (or their genre equivalent) showing up to drag you toward the plot is probably a good idea all on its own.

But the important point of making it a compel... if you do, then you're saying the player could buy out of it!  Don't make that offer if you aren't willing to allow that option!

Think of it this way: compel is way if rewarding the player for doing the hard work of creating conflict for you. If you trap him, you're doing the work. If he sees a trap, has the option to skip it, but goes for it anyway, reward his recklessness. He decides to tick off the bouncer with his smart mouth.? Point. He sees the bullies close around. The innocent schoolboy? Point. Or, it's backstory. You trap him ninjas, and the lead ninja is an enemy from his past. He helped make conflict.

Yeah Robert, two interesting posts today about Aspects and story juice.

Cable TV dramas have brainwashed me with the thematic stuff, so I like games that hover around an issue and pull it in again and again. So I'd go for tying GM intrusions to a really small handful of Aspects, whether plot-wise (maybe the current issue and impending issue), or theme-wise (one global Theme Aspect?), or character arc-wise (the group I'm in has tried using a "Kicker" Aspect for each PC to describe the desperate motivation that's "compelling" each of them along).

+Mark Arndt - The Kicker thing sounds neat- any chance you could elaborate?

Sure! The term Kicker comes from Ron Edwards (of Sorceror fame) and refers to the initial incident, which requires a huge choice from the character and propels their story thereafter (will Luke leave Tatooine and become a Jedi like his father, or bury his aunt and uncle and get on with moisture farming?). It launches the character on their story arc.

For Fate, I think it could just be a PC's Kicker Aspect with the normal mechanics. The GM can compel it to add developments to that story arc (or be bought off). The player gets more permission (than usual?) for adding story details and coincidences when spending a fate point on their Kicker ("Vader's on that ship. I'm endangering the mission"). It's the lever the player gets to pull to really move their own story the way they want to move it.

Could be too meta for some players, so seems best to check in and see who wants to use it and who doesn't.