American SIS or SPA?

I always wanted to go into international relations as, at least, my graduate study, in order to get jobs that correlate with it (ambassadorship, diplomacy, foreign work, etc)

As of recent, I’ve been pretty set on pursuing Polisci/Econ double major, as IR in itself is part of Polisci, and it seems too binding for my future career, so early on. Nevertheless, once I toured American, I saw that SIS seems to be getting a lot of attention financially and from the faculty that praises it for being new and highly ranked. If my final goal of education, as it seems right now, is to pursue IR, would it make sense to double major in IR/Econ, or should I ignore the rankings and still do Polisci/Econ for broader graduate school opportunities?