I think being looked at as 'foreign' and not speaking the native language when traveling can make it difficult to feel competent when trying to communicate. I can only imagine the longer term impact of moving somewhere where the native language is not your own. Finding housing, a job, different foods, different styles, trying to learn, etc., is probably intimidating. However, I also want to mention that even traveling between countries that speak the same language often have differences that, while smaller in comparison, also impact communications.