it may not be fear. It could be as simple as the policy of no compromise. The art of doing any deal is twofold: have you gotten as much concession as possible, and if so, are you better off with the deal than without. In this case, the answer to both is yes. It's not a perfect deal, but the options to a deal are killing people who don't pose a imminent threat, and until W that precluded military force, and the Tea partiers simply don't accept taking any compromise.
You buy into the notion that our choices are accept a deal at any cost or invade Iran. That is patently untrue.
As Netanyahu stated in his speech - the alternative is to agree to a better deal.
There's not going to be a better deal, because if the US walks from the deal, the intl support for sanctions will crumble and Iran won't need to deal. Russia will probably give them enriched uranium just to spite us at this point.
And that's Bibi's end game. He doesn't want a deal because that's his excuse to be the only person who can save Israel. And, he's not going to bomb unilaterally, because the entire world will demand his economy be shattered. Or if he does bomb, Iran wins.
Mr. Netanyahu also was very clear when he stated Iran needs a deal more than we do. We have to be tougher on Iran and be willing to call their bluff. If diplomacy won't work Netanyahu has made it clear that Israel will take matters into their own hands.
We only have leverage over Iran if other nations will support sanctions. We don't have the power to simply crush Iran's economy without the EU and China ... and Russia.
If we walk away from a ten year deal, there isn't going to be support for sanctions. There was not when W was potus. Without sanctions, Iran gets the world off it's economy's neck AND keeps all the centrifuges. Then, we're back to our only leverage being ... bomb them.
Bibi's playing a bait and switch game. He's offering a better deal, when there is none, and the switch is bombing Tehran. That's what he wants. If Iran is no longer a threat, he has no enemy. And, his only justification for keeping a pale state from happening (and keeping the land) is that it's necessary to protect against a threat. He's got to have territory to keep the rockets away.