Please note, there are massive spoilers within this question so I've hidden them. If you haven't read at least Chapter 83, and later in this question 94, this question will spoil the events that occur in 83-94.
In Volume 21, Chapter 83, Pages 14-19 of the Attack on Titan manga
I have been trying to understand what Zeke means by this statement. So far, what I've gathered is that
Zeke and Eren share the same biological father but Zeke refers to their father as strictly Eren's father. Zeke believes that "Eren's father" brainwashed the two of them and Zeke made it clear that he understood what Eren was currently going through.
However, given that
anyone fighting in the Eldia vs Marley conflict seems to have a very biased view of historical events,
I can't tell the extent of the truth in Zeke's statements. Later in Chapter 94, Zeke makes some statements about
the value of titans when human technology was about to, or already is, surpassing them. And he expressed his concern for the survival of Eldians should they no longer be useful to the world.
So, how is it that Zeke thinks he is going to someday save Eren if
Zeke is working for the one nation that seems most interested in getting rid of the titans should they prove to have little or no military value?
Is the statement Zeke makes to Eren in Chapter 83, page 19 referring to something less obvious than what is mentioned on pages 14-18?