I’m not sure that thought (that we’d lose so much we’d give up) was ever a reality as much a hope by the Japanese. I truly believe they read America wrong (fat, lazy, self-indulgent) just like Hitler did.
The fact that we believed Japan committed a unfair sneak attack and killed innocents meant we would never just walk away without taking a huge pound of flesh for it.
They lost when they launched the first aircraft on Dec 7th.
If the Japanese declaration of war happened on Dec 6th, things would be different. Of course the idiots in the Japanese Embassy taking all morning to decipher the coded declaration hurt, too.
Unfortunately we've taken the opposite tack since 9/11. Giving our monstrous enemies light wrist taps instead of the scouring they have earned out of fear that our own traitorous media would say bad things about us.