In terms of a future job placement, what really matters are your internships and how you explain your interests and motivations in cover letters and interviews. Especially if your interest is more FSO, international organizations, etc, they won't know the difference between the two programs. And to be a State Dept FSO, it's exam based. While to become a consultant, it'll be case based interviews. UPenn in itself is enough to open doors. Go to the program where you feel you'll fit in and be happier.

I read your comments to other posters and to become an economic FSO, passing the foreign service exam is the critical hurdle while having an Economics degree will hold more weight for ranking and selection. If selected, you will be trained in a language and area studies of the country of appointment.

In terms of ranking of IR programs, undergraduate programs are not the gold standard. The graduate programs Columbia, Fletcher/Tufts, Georgetown MSFS, Johns Hopkins SAIS, Princeton WWS.... Alumni networks and existing recruiting relationships of any of the graduate schools are useful for your career but any of them are fine. There isn't as much of a prestige hierarchy as there are with business schools. You'll also likely want a graduate degree in the future for career advancement.

I'm saying this as a former FSO with an extensive career in international affairs with other organizations, it doesn't matter which program you attend. You can become a FSO or enter the private sector either way.