Here is an interesting story about how Iran spoofs shipping tracking systems to move banned oil products:
Iranian oil tankers are sending incorrect satellite signals that confuse global tracking systems and appear to conceal voyages made by other ships to Syria, which, like Iran, is subject to international sanctions.
The two countries are close allies and have helped each other deal with shortages by swapping badly needed fuels such as gasoline for diesel.
Over time, any new sanction can be coped with. And gradually tightening them just gives Iran time to adapt.
UPDATE: This Op-Ed from an analyst at the Army War College's Strategic Studies Institute argues that sanctions could work. I tend to think that anything short of a blockade that starves Iran into submission won't work, in no small part because Iran has gotten good at evading and coping with sanctions.
And we won't starve Iran into submission. We didn't do that to Saddam's Iraq and still we were accused of starving babies there with sanctions.
