I must be too simple minded.
If you are going down, and you don't want to, and all you need is more HP (that you don't unfortunately have) then it is SWP.
If you are going down, and you don't want to, and more HP makes it worse, or at least no better, then you are VRS.
If you start out with SWP, and more HP doesn't stop it, you may end up in VRS.
Two terms. SWIP and SWEP. Insufficient power, or excess power.