Abraham and Isaac - Cowards?

When the men who lived there asked Isaac about his wife, Rebekah, he said, “She is my sister.”  He was afraid to say, “She is my wife.”  He thought, “They will kill me to get her, because she is so beautiful.” [Genesis 26.7]

There is obviously some cultural thing regarding men and their wives in the time of Abraham and Isaac that we are not aware of.  Either this is true or else both Abraham and Isaac were simply terrible cowards. 

Did they not think this through?  Was there no concern that their wives would be taken (as was Sarah initially) to be come someone else's wife?  What was it about the marriage relationship that was so unimportant so as not to defend it?  I continue to be puzzled by this action by Abraham and  Isaac.

Frankly, the Bible (as a whole) depicts women in a much different cultural role than women today enjoy.  They were seen as more of a commodity back then.  And yet, the Bible is full of true love stories - Isaac and Rebekah being one of those stories!  Go figure!

Hmm.

Father, I make no pretense of understanding the relationships depicted by Abraham's and Isaac's obvious self-preserving actions regarding their wives.  I don't mean to pick apart Your Word and Your people, but do these things not matter?  How can we read about Abraham and his offspring and regard them with any respect?