Difference between 守らせてあげる and 守ってあげる


What do both translate as and why?

守ってあげる is basically protecting something. The original was 約束守らせて上げられなくて御免なさい
which I basically translated as, I am sorry that I couldn't (be made) to keep
the promise I made with/to you/me?!?




> 約束を守ってあげられなくてごめんなさい。

would mean "I'm sorry I can't/couldn't keep my promise (that I made to you),"
while:

> 約束を守 **らせ** てあげられなくてごめんなさい。

means "I'm sorry I can't/couldn't let you keep your promise (that you made to
someone/me)."

守らせる is the causative form of 守る. So, in the first sentence the subject of
約束を守る "keep a promise" is the speaker, and in the second sentence it's the
hearer.

