Most accurate analysis till date.
They sing it because of their requirements. Senators act on lobbies, and lobbies are payed for.
So essentially, it depends on the lobbyists. The Saudis pour billions into these while Israel has the Jewish population that supports the Zionist cause to pay for it.However, these lobbys do not control European ones and the US can ill afford a disengagement with the Europeans such as what happened in the Iraq war(except the 51st state thanks to Blair).
So the senators and congressmen must play a delicate balance of a gentle Iran while keeping their allies happy.
As such, they may seek to break up Iran in the same manner as they wish for Pakistan to carve out further territories. But realistically they would rather have a pacified Iran. Even Israel doesnt neccecarily need to stop bashing Iran even after peace overtures as it still needs a threat to justify spending on defence(It is after all a model democracy and accountable to its people). If Iran is to go pro US and shut up on Israel.. they will need to create another threat. Egypt might be a candidate but that is just conjecture...so Iran still had the role of Bogeyman to play. At the end, there will be NO conflict between Israel and Iran but it is quite likely the Middle east may be plunged into a "Muslim" Civil war with the GCC against the Iranians to essentially destabilize and devastate the area for future needs.