Ruling on sponsored students staying in kaafir countries
Question

                We are Muslim students who are studying in America for periods ranging from six months to four years. We have come here to study simply because we wanted to – i.e., we are not sponsored by anyone – and the studies here in America are no different from the studies back home, apart from the fact that we will learn English too. What is the ruling on our staying in this country to study? May Allaah reward you with good.
Praise be to Allah.If
      you have knowledge and understanding of the religion of Allaah that
      enables you to call others to Allaah and teach the people good things, and
      refute specious arguments and practise your religion openly among the
      kaafirs around you, then it is OK, because if a person who is as we have
      described and who has equipped himself with knowledge stays there, he can
      benefit himself and others. Allaah may guide many people through him if he
      strives hard in da’wah and is patient, and his intention is sincerely
      for Allaah alone. But if a person does not have this religious
      understanding or he does not have the patience for da’wah, or he fears
      that he may fall into things which Allaah has forbidden, or he cannot
      practise his religion openly by calling others to worship Allaah alone and
      warning them against shirk and explaining that to the people around
      him, then it is not permissible for him to stay among the mushrikeen,
      because the Prophet  (peace and blessings of Allaah be upon him) said:
      “I have nothing to do with any Muslim who settles among the
      mushrikeen.” And because of the danger to which he is exposed by
      settling among them. And Allaah is the Source of strength.