Iran Buying More From US In Spite Of Tensions

Reinsch said he is hearing from more businesses interested in Iran. But beyond an effort by the Obama administration to encourage talks with Iran, he hasn't seen any policy changes that would lead to more opportunities for U.S. businesses.

Humanitarian shipments are an example of the tricky line the United States has walked in dealing with Iran — even more so during Iran's election protests.

Obama has proceeded carefully when commenting on uprisings in Iran over President Mahmoud Ahmadinejad's disputed re-election, saying he shared the world's "deep concerns" but that it wouldn't be productive "to be seen as meddling."

In allowing exports of necessities such as grain and medical supplies, the U.S. has tried to send a message to the Iranian people that it is a friend to them and has no interest in punishing them for their government's policies. At the same time, by helping Iran feed and provide medical care to its population, Washington can't help but provide an unintentional benefit to the Tehran government.

U.S. penalties seek to undermine that government far more than aid it, by withholding technology, equipment and money that would allow it to build its military and industrial base, particularly the oil industry.