Original sentence: First world governments have speculated that some foreign women marry men in their country as an easy immigration route, staying married long enough to secure permanent citizenship, and then divorcing their husbands.Great Britain and Australia have experienced similar immgiration and are trying to deal with the issue
Edited sentence: First world governments have speculated that another reason for foreign women, marrying men in their country, is to provide an easy immigration route by staying married for a period of time sufficient to secure permanent citizenship, and then divorce their husbands.Great Britain and Australia have experienced similar problems and are trying to deal with the issue