Do you advice brothers to marry within their country or the country .....

The main purpose of marriage is sukoon (ease,comfort).  Both the spouses give and derive comfort from each other.  In order to achieve this, both spouses must be on the same wavelength.  They must be compatible and understand each other.  If the spouses are not on the same wavelength and do not understand each other it will not be possible for them to give and derive comfort from each other.  In such a situation, each spouse will relate and express him/herself in a way that is not acceptable to the other and that will lead to fights and disputes.  The marriage now will not be a means of peace.  It will be a means of fights and disputes, thus defeating the very purpose of the marriage being peace and comfort.  It is therefore important to consider cultural practises when choosing ones spouse.  If both spouses deep cultural differences as well as each spouse being deeply connected to his/her culture, those cannot be compatible in marriage.  This does not mean that spouses from different cultures cannot be compatible to each other.  If the spouses are not deeply connected to their cultures and they are tolerant, then there is a possibility of compatibility between two spouses.  The issue also largely depends on individuals themselves.  It is possible that people of a particular culture are dedicated to that culture but some people of that culture may not be so.  In that instance, cultural differences will not significantly impact on the issue of compatibility.  In brief, the issue is of compatibility between the spouses.  Cultural differences could have an impact on maintaining or eroding compatibility in between the spouses.  Much also depends on the individuals themselves.