No one, absolutely no one, really believes sanctions will stop Iran’s program of nuclear development. At best, sanctions will simply cause the Iranians to hide their assets more cleverly.
The people who make policy for the U.S. are not dumb. Actually, they are quite smart! They know sanctions are absolutely useless. So, why are they playing around? Why haven’t they already hit Iran with a decisive "knock-out"
Why haven’t they already hit Iran with a decisive "knock-out" blow? 
blow?
Because Big Oil wants a Nuclear Iran.
The Iranians first target will not only be Israel. They will hit various European capitals and the Saudi Oil fields. Oil prices will sky-rocket. The oil-holdings of Big Oil off the U.S. coast and other areas will be worth a fortune. The U.S. military will then finally be allowed to use its Nuclear capability to hit Iran. They will use neutron bombs that leave comparatively little residual radiation.
With the Saudi fields gone, Big Oil will be asked to step in and get the Iranian fields up and running at full production.
Of course, in the meantime there will be a total global breakdown. Factories will close; business activity will grind to a halt. The poor will starve. The wealthy will not be able to use their cars.
Martial law will become the norm, even in the United States. [Ever wonder why FEMA has built large scale detention facilities in the U.S.?]
What can you do about this? Well, try your Congressmen, and then start storing dried foodstuffs and lots of water.