The Senate voted 67-31 on Tuesday to confirm Dr. Katherine Engel as Undersecretary of the Treasury for International Affairs, filling a position that has been vacant for nearly five months and plays a central role in the design and implementation of U.S. sanctions policy.

Engel, a former senior fellow at the Center for a New American Security and a career Treasury official who served in the Office of Foreign Assets Control during the Obama and Trump administrations, was confirmed with bipartisan support, a rarity for senior nominees in the current political environment.

Why This Appointment Matters

The Undersecretary for International Affairs oversees the Treasury Department's engagement with the International Monetary Fund, the World Bank, and foreign finance ministries. More importantly for current policy, the position has de facto authority over sanctions architecture, the design of financial restrictions that have become America's tool of first resort in geopolitical confrontation.

Engel's academic work has focused on what she calls "sanctions sustainability," the challenge of maintaining the effectiveness of financial restrictions over time as targeted countries develop evasion strategies and as secondary sanctions strain relationships with allied economies.

Her confirmation hearing was notable for the specificity of her criticism of current sanctions policy. She described the existing Iran sanctions regime as "structurally sound but operationally degraded" and characterized Russian sanctions evasion through third-country intermediaries as "a solvable problem that we have chosen not to solve."

The Policy Implications

Engel's appointment is expected to accelerate several policy initiatives that have been stalled during the vacancy. These include a comprehensive review of China-related sanctions authorities, the development of a new framework for cryptocurrency-related sanctions enforcement, and the negotiation of sanctions coordination agreements with the European Union and the United Kingdom.

The cryptocurrency question is particularly urgent. Treasury officials estimate that between $8 billion and $12 billion in sanctions-evading transactions flow through decentralized finance platforms annually, a figure that has roughly doubled since 2024. Current enforcement tools, designed for the traditional banking system, are poorly suited to this challenge.

Congressional Expectations

Both parties have signaled that they expect Engel to deliver results quickly. Senator Tim Scott of South Carolina, chairman of the Banking Committee, used the confirmation hearing to press Engel on Chinese banks that facilitate sanctions evasion on behalf of Russian entities. Senator Elizabeth Warren of Massachusetts focused on the adequacy of Treasury's enforcement resources.

Engel committed to providing Congress with a sanctions effectiveness review within 120 days, a timeline that Senate staff described as ambitious but necessary.

The vacancy at Treasury coincided with a period of significant sanctions policy activity, including the expansion of secondary sanctions targeting Chinese financial institutions and the renewal of the Iran nuclear-related sanctions framework. Career officials managed these processes competently, but the absence of a Senate-confirmed leader limited Treasury's ability to initiate new policy directions.

That constraint has now been removed. What Engel does with the authority will be closely watched in foreign capitals as much as in Washington.