The U.K. and U.S. are scrutinizing $20 billion worth of Tether (CRYPTO:USDT) transactions processed by Garantex, a Russian crypto exchange hit by U.S. sanctions, highlighting the challenges in curtailing Russia's access to foreign funds amid  geopolitical tensions.

These transactions, which could mark the most significant breach of sanctions since Russia's Ukraine invasion in February 2022, point to digital currency's role in sustaining the Russian economy by bypassing international restrictions.

Despite the extensive sanctions regime, Russia appears to leverage digital currency transactions and crude oil sales as crucial lifelines, prompting the Biden administration to tighten its focus on crypto exchanges and issuers like Tether.

While the probe has yet to pinpoint any violations by Tether, the stablecoin issuer asserts its compliance and cooperation with authorities, emphasizing the traceability and control over its digital transactions to aid law enforcement efforts.