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, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
It is permissible, Allaah willing, for the child to wear such clothes as long as it does not imply a religious violation such as if these clothes may bear images of non-believers or the like. However, the fact that these clothes are imported from non-Muslim countries is not a valid reason under Sharee`ah (Islamic law) not to wear them. It is an obligation on the wife to obey her husband concerning the dressing of their child, since the husband is not commanding her to commit a sin or a wrongdoing, especially that the interest of the child may require getting him accustomed to wear fully modest clothes, particularly when he reaches the age of discretion.
Furthermore, it is worth mentioning that one of the greatest and most significant purposes of Islamic Sharee'ah in the legislation of marriage in Islam is to attain mental and psychological stability. Hence, the spouses should spare no effort in their attempt to attain this great objective by living together in kindness and honorably, and through understanding how to solve the disagreements that might emerge as they try to reach common ground. Moreover, they should steer clear of the causes of disagreements and discord as it has evil repercussions.
Allaah Knows best.