Are there any internationally recognized journals on contemporary graphic design? For example, where can I find critiques, reviews, and argued opinions of designers like David Carson or Uwe Loesch?
There are quite a few journals indexed in the Design and Applied Arts Index (DAAI) which can be accessed through ProQuest.
Eye, the International Review of Graphic Design is one other journal.
Gemser, et al. (2011) have surveyed the top industrial design journals by popularity and average ranking. They are not specifically dedicated to graphic design, but many sub-fields of "design" are interdisciplinary and you might find something there.
Otherwise you might try international magazines rather than journals.
Gemser, G, Bont, C de, Hekkert, P & Friedman, K 2011, 'Quality perceptions of design journals: The design scholars’ perspective', Design Studies, vol. 33, no. 1. www.sciencedirect.com/science/article/pii/S0142694X1100069X