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.
There is no doubt that it is best for one's wife and children to stay where he lives, as in this case he will keep himself and his wife chaste, he will take care of his children and achieve other benefits. Therefore, if you can bring your wife and children to live with you or if you can go back to your country and be content to live meeting your necessities only, then do so. You never know, Allaah may facilitate for you the means of sustenance which you never expected. However, if none of these two options are available, and your wife permitted you to be absent from her for more than six months, or that you are in need to be absent from her for this period, then it is permissible to do so, but you should endeavour to return to them at short intervals of time according to your ability. You should keep your wife and children in a place where you feel secure about them but you should always contact them and ask about them. You should refrain from committing sins and must stay away from anything that could lead you to commit Zina (fornication or adultery). If this cannot be achieved except by bringing your wife to live with you or by marrying a second wife in the country where you work, then you are obliged to do so in order to avoid committing what Allaah has forbidden.
With regard to doubting the morals of your wife; if you have no evidence about this, then this is not permissible as in principle a Muslim is innocent until he is proven guilty.
For more benefit, please refer to Fataawa 94245, 90778 and 85711.