Meaning of 果たせることが出来たなら


I'm looking for some assistance in understanding the second line in the below
as I am not quite sure what 果たせる is referring to (I know what 果たす means in
e.g. 目的を果たす). I am not sure if there is something in context that I am missing
or not.

To provide some basic context、the village chief wants the young ones to leave
the village and see the outside world (The one currently talking is actually
someone who has come from the outside world, and the village chief has asked
him to take her outside with him). They ask to stay and he thought that they
were only saying this because they thought it was their responsibility to stay
in the village. They clear up his misunderstanding about why they want to stay
in the village.

> 「ですから、村長さん。送り出すのではなくて、どうか許しをください」
>
> 「 **果たせることが出来たなら** 、どうか、俺たちがここで暮らすことを許してください――」

