And I disagree that men should have the right to leave if they've given their word. It's really simple, if the man says he doesn't want the kid, he's off the hook, if he says he wants it and reneges later, he's legally responsible. It would be very easy to enforce.That's a bit more Government in my bedroom than I'd like, but it's at least a more rounded perspective. However, again historically speaking men HAVE had the right to opt-out. They would just leave and women had no legal recourse.
I don't see how the current status quo of forcing men to pay no matter what is any less government than this scenario. Government wouldn't even need to get involved unless someone violated the terms of the contract.