Should I use "who" or "whom" in "The main problem of Argentina comes from whom has taken office."?

Question

Should I use who or whom in this sentence?

My logic

I know that whom is an object pronoun, that whom has taken the office is the object, and that The main problem of Argentina is the subject.

I also know that who can be replaced with subject pronouns such as he, she, they and whom with object pronouns like him, her, them.

My confusion comes from the fact that I can replace it both ways:

Here Him replaces whom has taken office.

Here He replaces who.

That leads to my second question: can you use whom and who interchangeably when it’s the object?

If you're unsure whether to use whom or who, Don't Use Whom. — John Lawler, May 26 '22 at 23:11
Who is the subject of the verb has taken just as office it that verb’s object — whereas the entire clause Who has taken the office is in turn the object of from. These are different things completely. A clause can itself be a grammatical object; you never mark what's in the clause based on the clause's own grammatical role. You only inflect single words for case, not entire clauses. You cannot use whom as the subject of a verb, and since you need a pronoun inflected as a subject, it *must* be who. And this is a duplicate, which I shall locate momentarily. — tchrist, May 26 '22 at 23:42