Jim wrote,
Can jealousy ever be to extreme or overly irrational? Can control be the underlying issue?
Actually Jim, I believe jealousy is entirely a control issue. I write this knowing full well that I may not be addressing the specifics of your question, but hopefully it will relate.
In our culture we deem jealousy a negative and undesirable trait. Yet, one of the first attributes we are told about God is that He is a jealous God (Exodus 20:5). Later, Paul declared that he was jealous over the Corinthians with a godly jealousy (II Corinthians 11:2). I don't think we want to describe our Lord or His servant Paul as having negative or undesirable traits. What we need to understand is that jealousy like fire is good in its proper application, but when used improperly can be destructive and dangerous.
Jealousy in its proper application is the act or emotion of a possessor and protector. Our Lord is jealous over His name, character, creation and the redeemed. Paul was jealous over the Corinthians, who he considered his spiritual children. He had led most of them to Christ and taught them. In both of these instances, both the Lord and Paul had possession or authority over that which they were jealous. They both operated in protection mode for those under their care and possession. This is good and right. God and Paul are our examples. In the law given to Moses for Israel, there was a test to be administered if a man was jealous over his wife and feared she had been unfaithful. The test may seem insignificant to us and we may think it silly, but it was a serious matter. I only mention this to point out that, no where in the explanation of this test is the husband criticized for exercising jealousy (Numbers 5).
Jealousy becomes a problem when one exercises jealousy over someone or something that does not belong to them. Hence, God is correct being jealous over that and those that belong to Him, but we would be in error being jealous over God in anything. Paul would be correct in being jealous over the Corinthians, but they would be in the wrong to be jealous over him. When we take this principle into the marital realm, a husband would be right to be jealous for his wife/wives and children, but it would be wrong of wives or children to be jealous over the husband or father. The reason for this is that wives and children do not have control over the husband/father. Husbands and fathers have control or authority over their families as designated by God in His design for the family. Mothers would be correct being jealous for their children (as long as it doesn't conflict with the father), but children should not be jealous over the mothers. When wives behave jealously toward their husbands, they are in essence behaving as if they have authority and/or control over the husband, which is contrary to God's design for the family. Such behavior is in direct conflict with the Biblical principle of headship as taught in I Corinthians 11.
There is no scriptural grounds for jealousy between sister wives, since the husband does not belong to either, but both to him. Jealousy is a problem when unauthorized people attempt to exercise control. A wife's proper role is to be submissive to her husband and subject to his leadership, not controlling.