Sometimes it's not that straightforward.
Queue in the woman running along the cliff in the dead of night. Twenty feet behind her is a psychopath. Forty feet behind her is the man of her dreams.
So is this a thriller with a psycopath, or a romance tale with the man of her dreams?
The tale is in the eye of the beholder. Maybe the man of her dreams actually sees a beer stand about a mile ahead and he's sprinting to get there and quench his thirst from all this running. Maybe the psycopath is tired of his evil and mayhem, and is chasing the woman to profess his love and adoration. Maybe the woman is just jogging because she just ate a pound of raw cookie dough and has no idea these idiots are behind her.
My point? The Powers that Be created Romantic Suspense to resolve this dilemma. And I am darn glad they did! Because I, as a writer and reader, need a little bit of both in my life.