Maybe not inevitable for the US, Reg, but an Israeli airstrike against the reactor is a real possibility.  I agree with you in part, in that I don't think US groundtroops will be sent there.  

As far as Obama's stance, he has repeatedly stated that he will "negotiate" with Ahmedinejad.  This gives me great cause for concern, and I totally understand AIPAC's anti-Obama stance, at least in that regard.  Albeit Obama did elaborate (I heard him talking specifically about this on NPR), and stated that those negotiations would be one-sided, more in the nature of ultimatums directed towards Iran, but I think any attempt to "negotiate" otherwise with somebody like Ahmedinejad worries me.