It definitely depends on the country, but it also depends on what type of job you want in that other country.

If you want to tutor English in China, it’s not really mandatory to know any Chinese.

But, if you want a challenging job that you might have in the US (or in a country with your mother tongue), then you become more and more limited if you’re language skills are not up to par.

For instance, if you can’t read academic papers or newspaper level of writing, then you’re not going to be a research analyst.

If the business language of that foreign country is not English, then chances are you’re not going to be on the sales team and you can’t help draft documents or presentations.

If all your coworkers and bosses predominantly use the host country’s language…well, then obviously, you need some way of communicating with them.

On the other hand, if your role is interacting with say US employees stationed in that country, then you’ll be fine performing whatever business tasks required except for maybe directly interacting with the local team.