I’m interested in foreign relations, law, business, lots of things. So I was planning on ECON major since it’s versatile (tell me if this is or isnt a good major for my interests).
If you are ambivalent about a pure economics major (and your “worth it” question certainly implies that you might find that painful), then you might prefer something more interdisciplinary like one of the PPE (philosophy, politics, & economics) or PPEL (PPE + law) programs.
Pomona, Claremont McKenna, and Scripps (if you’re female) have a strong PPE program
https://www.pomona.edu/academics/departments/philosophy-politics-economics
https://catalog.claremontmckenna.edu/preview_entity.php?catoid=17&ent_oid=730&returnto=1494
http://www.scrippscollege.edu/news/features/the-scripps-experience-beyond-the-elms-the-off-campus-major-at-scripps
Other possibilities:
University of Richmond https://ppel.richmond.edu/index.html
University of Pittsburgh http://www.honorscollege.pitt.edu/academics/politics-and-philosophy-major
Tulane https://catalog.tulane.edu/catalog-15-16/majors/pecn.html
Denison University: https://denison.edu/academics/philosophy-politics-economics
University of Arizona (Honors College) http://www.u.arizona.edu/~ggaus/
Are you interested in econ? If so, then it’s worth it. Most liberal arts colleges and even a lot of the Ivies do not offer undergraduate business disagrees (Penn and Cornell are the exceptions, I believe), so econ is the gateway major for a career in business if one attends these sorts of schools. If you are interested in business, there are plenty of colleges that offer undergrad majors in business in general or more specific degrees (finance, marketing), though it sounds like you are interested in a broader perspective (you mention law, foreign relations), so, yes, econ would be a broad degree that should have course offerings that touch on these other issues.
If you are asking if econ is worth it from a job perspective, well, there’s good news and bad news. The good news is that the economy continues to improve. The bad news is that economics is being studied by seemingly everyone right now. Okay, “everyone” is hyperbole, but nearly a third of students attending Ivies are studying economics. It’s also the top major at Williams, Amherst, and the famously progressive Wesleyan. You won’t be alone if you choose econ as a major. 
I like @aquapt 's reminder that there are interdisciplinary majors out there. If you attend a LAC, double-majoring is also possible to complete in four years, opening up lots of cool combinations.
Are the interdisciplinary majors sutch as PPE as versatile as a pure economics degree?
Yes. Great versatile degree… Combine it with something else to make it more interesting and delve in further.
If you are interested, absolutely go for it. However, if you are only considering that major because you believe it must encompass all of your strengths or interests, do some research on the types of classes you would be taking and see if they interest you.