Just like clockwork, with the AIPAC policy conference set to begin this weekend, Congress has introduced a new round of draconian Iran sanctions. 
S.908 and H.R.2194 would allow the President to shut down all operations of any businesses inside the US that have any connection to Iran’s petroleum industry.  That includes any company that helps ship the petroleum to Iran, the company that builds the boat that ships the petroleum, the insurance brokers who underwrite the boat that ships the petroleum…it goes on and on.  You’re all no longer welcome here in the US of A, thank you very much.
Senate Minority Whip Jon Kyl (R-AZ) put it bluntly to our allies — many of whom we’re asking for help from on any number of important things like Afghanistan, the economy, etc:

“You can either do business with Iran’s $250 billion economy or our $13 trillion economy, but not both.”

Eerily reminiscent of another “with-us-or-against-us” approach, no?
House Foreign Affairs Chairman Howard Berman (D-CA), the lead sponsor of the House sanctions bill, struck a bit milder tone with his press release this evening, saying:

I fully support the Administration’s strategy of direct diplomatic engagement with Iran, and I have no intention of moving this bill though the legislative process in the near future.  In fact, I hope that Congress will never need to take any action on this legislation, for that would mean that Iran at last has complied with the repeatedly-expressed demand of the international community to verifiably suspend its uranium enrichment program and to end its pursuit of nuclear weapons once and for all.

Forgetting for a moment that Obama’s intelligence chief has said Iran doesn’t have a nuclear weapons program to end…and looking past the fact that Berman is just repeating the Bush administration’s failed demand that Iran give up its uranium enrichment…whether it is deliberate or not, this new legislation hurts Obama’s diplomatic effort.
Many in Congress see this as a way to play “good cop, bad cop.”  But there is a danger that the bad cop won’t let the good one get a word in edgewise.  After thirty years, eight Congressional statutes, and over forty Presidentially-imposed sanctions, we can’t even let Obama open his mouth to talk to Iran without shouting him down with a call to cripple Iran’s economy?
The fact is, it’s not the threat of new sanctions that will change Iran’s behavior; it’s the promise of lifting the existing ones that will evoke good behavior.  That’s how it worked with Libya and South Africa.  We already have enough leverage to solve this problem, what we need is a Congress that will stay out of the President’s way.