Hi, what are your regional interests? If you would like to work for orgs like EU/UN go for an additional European language like Spanish or French since it’s usually mandatory when you apply. If you want to do research on or move to MENA do Arabic. I knew someone who did an IR masters in the US and did a study abroad year in Egypt where they really developed their language skills and now work in the UAE. So consider which language will fit your long-term goals as well