Of all the tools of foreign policy — diplomacy, aid, covert operations — economic sanctions may be the least sexy. Perhaps it is fitting, then, that the epicenter of the U.S. sanctions program against Iran is a little-known bureau of the Treasury Department familiar only to the most plugged-in of financial intelligence wonks. Now, after nearly a decade of quietly but persistently pushing for export restrictions and financial blockades, an unassuming trio of T-men — David S. Cohen, Daniel L. Glaser, and Adam J. Szubin — find themselves and their work in the spotlight as Congress and Israel push the Obama administration to get tougher on Iran to halt its nuclear weapons program.
It is a high-wire act for the Treasury’s Office of Terrorism and Financial Intelligence (TFI): Cohen and his team must craft policies that hurt Iran enough to force its leaders back to the negotiating table while trying to minimize damage to oil markets and allies like India and Japan that have agreed to participate in sanctions despite long trading histories with Iran.
Then there are questions about how effective economic sanctions really are, and whether they may backfire — unifying the Iranian public around their intransigent leaders. But sanctions are pretty much the only game in town right now when it comes to U.S.-Iran policy, despite a recent news report saying Iran had agreed to talks. (The White House denies it.)
The absence of other options puts pressure on Cohen, Glaser, and Szubin, who worked under Cohen’s predecessor, Stuart Levey, to help lay the groundwork for the sanctions that are now responsible for hurting Iran’s currency.
Cohen, undersecretary for terrorism and financial intelligence, is the group’s most visible member. The 49-year-old spends a good deal of time selling the sanctions program at home and abroad — and smoothing feathers when corporate interests are affected.
Szubin, director of the office of foreign-asset control, is a lawyer by training who joined TFI in 2004 when it was just getting off the ground. Glaser, assistant secretary for terrorist financing, joined the Treasury in 1996 as a junior staff attorney and worked his way up to director of TFI’s predecessor agency.
Their work across multiple presidential administrations (the U.S. has had sanctions against Iran for decades) suggests that Szubin and Glaser are more interested in policy than politics. They say national security is their priority and that it comes before concerns about the domestic economy or the impact of their actions on U.S. relations with Asian countries. The team is also clearly aware of its place in the broader effort to shift Iran’s nuclear calculations — and in the overall dance of diplomacy. “Sanctions are not a replacement for policy,” Glaser notes. “Sanctions serve a policy.” And so, while not very sexy, they may be the one tool left that can help prevent a new military confrontation in the Middle East.
This story is from the November 12, 2012 issue of Fortune.