NEW YORK — Here’s what happens when a business linked to Iran’s Islamic Revolutionary Guards Corps (I.R.G.C.) is targeted with sanctions. A representative of the Revolutionary Guards finds a lawyer in Dubai and says: “Look, I’m on this stupid U.S. Treasury list. I’ll give you 10 percent. Help me set up a shell company in Dubai or Malaysia.”

The Treasury Department enemy list (“Specially Designated Nationals”) is easy to find. It’s at www.ustreas.gov/offices/enforcement/ofac/sdn/. Revolutionary Guard tycoons in Tehran know that. Once they have a new shell company, say in a cousin’s name, they circumvent the list. They go on reaping the heady profits open to the in crowd when sanctions distort an economy.

Iran has lived with sanctions for a long time; its immune systems are highly developed. As much as 20 percent of the gross national product of Dubai is linked to Iran trade. I don’t see new “targeted” sanctions disrupting this traffic. Iran’s economy, even in a slump, is too big, too diverse and too sophisticated: North Korea it is not.

Still, thanks to Iran’s erratic response to President Obama’s overtures and its ongoing nuclear nationalism (a more coherent political than weapons program), the United States finds itself in lockstep toward new sanctions.