J.S.
Took me 30+ years to realize the answer to this
Neither.
Short fuse means I am like a child throwing a temper tantrum and not thinking it through.
Long fuse means I hold a grudge, which gets to be some pretty heavy baggage to carry.
I found that after I unloaded all that (I'm in recovery - so it was via the steps), I didn't want to go back to being either guy.
So with some practice, I try not to have a fuse at all.
I accept that life isn't fair, and I'm not in control of anyone or anything else - only myself and my own reactions. I try to let the actions of other people be their own, and try to see what role I played when I find conflict.
I must be feeling philisophical today. Or maybe just particularly sober. :)
ETA - Hmmm - i don't know if I'd consider 30 seconds of argument a short fuse with 10 min? being a long fuse. I see what you mean though. I guess people do tend to call it that.
I meant more of the weeks or months of holding in a resentment until it explodes (long fuse, imo) - or for the professional grudge holders like myself - holding on to resentments for decades. Yes, decades.