Whet??? Do you not know that there's a difference between fostering and owning? The dog is aggressive and can't be in our house.

It isn't fair to adopt a dog, only to just return them and pick another as you see fit.

Yeah, I didn't say I was just picking another dog so nice misquote.

What if the dog didn't exhibit this change in behaviour for 2 or 3 years, would you still just get rid of it?

Obviously no, but I'm not risking getting bitten or unsuccessfully training a dog over 3 years when such a thing is unnecessary for many dogs who don't exhibit such behaviour.

you're either prepared to take on the responsibility of a pet and everything that goes with it or you aren't.

Yes, because it's my fault 100% to not want a dog in my housegold who displays aggressive behaviour.

Have you ever even had a dog who has been extremely aggressive? You're acting like I'm leaving him on the street when his fucking previous fosters are literally coming back this evening to come get him.

Also I don't recall phrasing my OP as a plea for advice, so I'm not sure why this is a discussion to begin with.