U.S. lawmakers have urged the Treasury Department in a letter to improve sanctions enforcement against cryptocurrency crimes and “rogue states” such as North Korea and Russia in light of the ongoing war in Ukraine. 

The letter sent earlier this week is the latest sign of increasing awareness in Washington about the sanctions implications of emerging financial technology such as decentralized finance (DeFi), which allows criminals of all stripes to move cash with relative anonymity and well outside of current regulatory schemes.