The snapback of U.S. economic sanctions on Iran this week created “quite an introduction to the private sector” for John Smith, the former director of the U.S. Treasury Department’s Office of Foreign Assets Control who became a partner at Morrison & Foerster three weeks ago.

Smith said Tuesday his phone has been ringing frequently with inquiries that he characterized as “urgent”—from corporations and their general counsel seeking guidance on navigating the sanctions. The calls have been from all industries, he said, but especially the financial and trade sectors.