I have taken a vow to leave my foreign wife who has caused me endless trouble; she used to consume drugs, not to mention the evil habits and practices that do not suit us as Muslims. I had taken a vow never to have sexual intercourse with her unless she was already pregnant. I did not vow to divorce her because I cannot do so now as I am about to get my green card and obtain a work permit in that foreign country. If I leave her now, I would probably never get my greed card or work permission. Actually, I took that vow because I became certain that staying with her constitutes harm to me because she may get pregnant and my child will be raised in such an evil environment and have a mother whom I believe cannot be trusted to raise a cat, let alone what I discovered about her after marriage. I married her with good intentions, but I was forced to take that vow as I was in a terrible moral state. I said, "I vow to Allah, the Exalted, if He saved me from this disaster (i.e. her being pregnant), that I will never have sexual intercourse with her." I live with her in the same house, but we are not intimate. I come up with a pretext every time to justify keeping away from her because I cannot leave her because of the reason that I have just mentioned. My question is: is it forbidden to take a vow to not have sex with her although she is my wife? Note that marrying foreign women incurs a great deal of evil, and you know this fact more than I do. I am inclined to the idea of leaving her anyway, even if this would make me lose the opportunity to obtain a green card and work permission here. This is better than losing my Hereafter. What is your advice for me? I apologize for my prolonged question.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His Slave and Messenger.

We could not understand from your question whether your wife is a Muslim, a disbeliever, or from the People of the Book (i.e. a Christian or Jew). If she is a disbeliever and not from the People of the Book, then your marriage to her is invalid in the first place according to the consensus of Muslim scholars. In this case, you should separate from her. If she is from the People of the Book or a Muslim, then your marriage to her is valid. Nevertheless, if she is from the People of the Book or a Muslim and you married her without the permission of her waliy (matrimonial guardian), then such a marriage is invalid, according to the preponderant opinion, and it should be annulled.

If we considered the marriage valid and this woman is as bad as you have described her, then you should divorce her, especially given the fact that you do not have children yet. You have said that she is unable to properly raise children, especially in such countries where it is hazardous for both parents and children to live. Hence, if there is no considerable need or necessity for living in this country, then it is better for you to migrate to a Muslim country.   

As for a husband's vow never to have sexual intercourse with his wife, that is considered  neither binding nor valid. Nevertheless, it is more prudent (in terms of clearing you of your liability) to offer an expiation like that for breaking an oath.

Allaah Knows best.