U.S. economic penalties are proving harder to translate into durable behavioral change for adversarial governments as those states adopt elaborate measures to avoid them, according to a recent report. Policymakers in Washington are confronting increasingly complex networks that shield trade and financing from the intended effects of sanctions.
The measures come at a sensitive moment for diplomacy. Negotiations under a newly signed agreement are under way that would deliver sanctions relief in return for Iranian steps tied to its nuclear program and assurances on the unimpeded movement of shipping through the Strait of Hormuz. Those discussions follow an extended period in which the U.S. has ratcheted up economic pressure on Tehran.
Over the last 18 months, U.S. authorities have placed more than 1,000 sanctions on Iran as part of a broad effort to squeeze its economy. Nonetheless, Tehran has continued to generate substantial revenue during that period, largely by exporting oil to China. Reports indicate Iran's oil exports brought in about $43 billion in 2024, a flow that has helped sustain its economy despite extensive restrictions.
Facing the persistence of export revenues, the White House took the uncommon step of physically blockading Iranian ports in an attempt to curb shipments and increase negotiating leverage. The blockade illustrates the lengths to which U.S. officials have gone to try to limit Iran's ability to monetize its commodities.
The difficulty in enforcing sanctions is not limited to Iran. Russia, despite years of Western measures, has continued to finance its military campaign. North Korea has also expanded its nuclear capabilities while developing alternative financing methods, including cryptocurrency theft and overseas money-laundering networks.
According to the report, sanctioned actors are increasingly dependent on layers of intermediation to move goods and money. These techniques include the use of shell companies, third-party intermediaries and financial conduits situated in jurisdictions such as China, the United Arab Emirates and Turkey. Such arrangements enable continued trade and payments in ways that reduce the bite of direct restrictions.
China's financial system in particular has emerged as a critical channel for both Iran and Russia, offering mechanisms for payments and trade that help blunt the impact of U.S. controls.
U.S. officials have signaled an awareness that sanctions policy needs adjustment. Treasury Secretary Scott Bessent recently said that officials are reviewing sanctions programs that may be out of date and are assessing how restrictions can be applied more effectively. The focus on programmatic review reflects concern that existing tools may not be optimized for current evasion strategies.
Debate persists among former and current policymakers about the root of the problem. Some former officials argue that enforcement, rather than the design of sanctions themselves, is the central shortfall. Others contend that sanctions remain a meaningful instrument of statecraft when they are used alongside diplomatic and military pressure - even as targeted governments develop ways to blunt their effectiveness.
Implications
- Sanctions complexity is increasing demand for more nuanced enforcement and interagency coordination.
- Financial systems in certain jurisdictions are critical nodes that can limit the reach of unilateral measures.
- Energy markets and defense-related financing are among the sectors most directly affected by these enforcement challenges.