Richard D. Phillips shares the #1 threat in The Masculine Mandate:
“When Paul says that a husband must embrace self-sacrifice for the sake of his wife’s well-being, this of course includes her physical safety. But the main threat against which a man must protect his wife is his own sin.
A friend once expressed his awakening to this truth in these words: “I used to think that if a man came into my house to attack my wife, I would certainly stand up to him. But then I came to realize that the man who enters my house and assaults my wife every day is me, through my anger, my harsh words, my complaints, and my indifference. As a Christian, I came to realize that the man I needed to kill in order to protect my wife is myself as a sinner” This is exactly right.
Peter gets at this role of heart-protector by saying that we show “honor to the woman as the weaker vessel.” I earlier said that the word honor means to cherish the woman. When a man cherishes a woman, he not only nurtures her but also protects her so she feels safe from verbal abuse, ridicule, and scorn—especially his own—for those are darts that pierce her tender heart.”