Fault and responsibility

I've been pondering for a while that there is a shortcoming in the English language. If someone does something bad, it's their fault. If someone is in charge when a bad thing happens, it's their responsibility. But we don't really have a word or phrase to describe someone whose actions knowingly make it more likely that someone else will do a bad thing. It's not their fault; the person who actually does the bad thing needs to get the blame. They're not responsible for the bad thing, because they didn't do a bad thing and weren't in charge of making sure other people don't do bad things. And yet, if they hadn't done what they did, the bad thing would not have happened (or at least been less likely to happen).

This has been on my mind for personal reasons - during a disagreement, I used fault/blame language, implying that the person I was speaking to would be to blame if a third party did a bad thing, when what I wanted to say was that his/her actions were making it enormously more likely that a third party would do a bad thing; this did not do a lot to resolve the disagreement. I'm hoping that in the future I'll be wiser about using language that addresses causes without apportioning blame.

But in addition to my own experience, this distinction between fault and contributing cause also, I think, is very relevant to the latest outbreak of bloodshed between Israel and Gaza. If you're fed up with that whole situation and don't want to read about it any more, this is your cue to wander off; otherwise, read on.