This is smart. It is a first step toward removing the hypocrisy of the US promoting democracy, yet rejecting democratic outcomes we disagree with. It also promises to go a long way of tearing down the true sanctuary that we have built for these organizations with our previous policies. Hamas and Hezbollah both take sanctuary in the very fact that we hold them to be outside the state, outside the law. By recognizing and incorporating them into our state engagement we deny them that sanctuary, and the entire entices and populaces of Palestine and Lebanon come to be held to account for their actions. This is the best thing we could do to help Israel as well.

Yes. Once these organizations are recognized as true parts of the states they come from, the simple rule of "strong state trumps weak state" applies. The liability of the weak states they represent will open up these organizations to tried and true tools of deterrence. Currently they have sanctuary from the same.