I don’t know if there’s a single or simple answer to that question. I think the two categories each have their intwined marits.
Strength: When you express/show/demonstrate compassion one could be giving and helpful. The help offered could just be a shoulder to cry on or an ear to listen.
Either way it could save a life, provide clarity, open other options and/or a different POV. In this way one is sharing strength through compassion.
One could also argue that strength is compassion. It takes strength and confidence to show compassion to someone else, especially someone you don’t or hardly know.
Weakness: Compassion can be shown in an unhealthy and unhelpful way. Showing compassion to someone who actually needs some tough love, a dose of reality, or even to know/experience consequences of his/her action(s).
Maybe compassion isn’t exactly a weakness, but not the help someone needs at the time…? Listening to my fellow addicts talk, joke and even glorify their drug use, time in jail and even prison is discouraging if not disturbing.
It’s almost like rehab/recovery isn’t their actual goal. Like it’s “better than jail” or on the streets. So maybe there isn’t actually an answer to the question. Maybe the search for the answer is the point? (didn’t I hear that on Star Trek or something?).