America isn't going to do anything. Iran has shown neither the capability nor the intention of making trouble for an of its neighbors, let alone the USA.
GW Bush planned originally to invade Iran after finishing up in Iraq, but Iraq turned out to be more trouble than he expected. He desperately wanted to bomb Iran, just for his own political purposes, but he found he wasn't able to because Iran had wisely invested its money in defensive, not offensive capability. They are so well defended that we aren't about to bomb them just for shallow political purposes. So all Bush could do was to rattle the saber, to blame Iran for all his problems, which he did for the last six of his eight years in office.
Israel is not about to stage an unprovoked or pre-emptive attack on Iran for the same reasons--because they threaten no one and they bristle with defensive weapons.
Iran's political leaders are guilty of the same kind of overblown rhetoric as US political leaders, especially Republicans. Rattling the saber, hugely hyping the danger of allowing those countries whose leaders they disagree with to continue to exist. But it's just blather and everyone on both sides knows it. Iranian leaders have said Israel has no right to exist, and American leaders have said Iran has no right to exist, so perhaps there should be sanctions on both sides. 8^D