There are too many cases of U.S. sanctions outliving the circumstances that prompted them, with damaging consequences for the implementation of peace deals. For example, the U.S. government backed a 2016 peace agreement between the government of Colombia and the Revolutionary Armed Forces of Colombia (FARC), but sanctions against the FARC lingered for five years after the rebels gave up their weapons. Sanctions made it hard for them to open bank accounts, find jobs, and access credit. They were one reason why former fighters struggled to integrate into civilian life, and in some cases, decided to return to arms.

Sanctions left in place after political transitions or the end of wars block economic recovery.  After the Taliban takeover in Afghanistan, the U.S. sent aid to the country and declared the need for post-war economic recovery – even as U.S. sanctions hobbled the economy. The Biden administration tried to ease the sanctions’ impact with a spate of Treasury licenses permitting business activities, but the chilling effects of sanctions persisted. To be sure, sanctions were not the only reason for private investors’ aversion to working under Taliban control, but dozens of businesses have said that sanctions (and confusion about them) forced businesses to err on the side of caution and suspend investments in the country.

Sudan offers another case. The United States lifted trade restrictions on the country in 2017 but a state sponsor of terrorism designation persisted until 2020, despite the fact that a new civilian-led transitional government had replaced strongman president Omar al-Bashir, whose abuses had motivated the sanctions. To end a country’s state sponsor of terrorism designation, the President must certify to Congress that the country has undergone a fundamental change in leadership and ceased supporting international terrorism. With the transitional government in place, and with Sudan having been a U.S. counter-terrorism partner for some years by that point, it appears Sudan had fulfilled these criteria – but the designation nevertheless remained. Lingering sanctions contributed to firms’ decisions to withhold investment, despite a campaign by U.S. officials to encourage economic activity in the country. They also limited the financial support available to the transitional government, deepening an already dire economic crisis and contributing to conditions that brought about the removal of that government in a military coup in 2021.

Sanctions can pose major hurdles for non-governmental peace organizations that do the behind-the-scenes work of nudging parties toward conflict resolution. Such work often involves facilitating conversations between conflict parties, but the U.S. government sometimes deems these conversations illegal. Take a dialogue that was meant to take place in Lebanon with the participation of political leaders, several of whom were sanctioned by the United States, with the aim of forging deeper understanding of the motivations of prominent actors in the region. The U.S. Treasury told the organizers that facilitating the dialogue was a violation of federal law, and that going ahead could subject them to criminal and civil liability. Because of legal risks such as these – and also because of the administrative burdens and operating challenges involved in navigating economic restrictions – non-governmental peace organizations often pull out of, or reduce their activities in, sanctioned countries.

At the negotiation table, U.S. officials complain of being hamstrung from using sanctions as leverage. Some have found that they cannot promise effective or sustainable sanctions relief — at least not credibly. This was a problem when the Biden administration tried to re-enter the 2015 nuclear deal with Iran. Iranian negotiators sought guarantees that sanctions, once eased, would not be re-imposed. After all, the last time the U.S. lifted sanctions in step with Iranian significant nuclear concessions, then-President Donald Trump pulled out of the deal and reimposed them despite Iran’s full and verified compliance with its nuclear commitments. American diplomats had no way to guarantee that any deal involving sanctions relief would be long-lasting.

U.S. negotiators also find it difficult to encourage behavior change when sanctions targets know little of why they are sanctioned or what they can do to get off the lists. This happens surprisingly often. Members of Venezuela’s electoral authority who were sanctioned in 2020 were unsure of why they had been placed on U.S. blacklists and left in the dark as to how they could get off them. Others only hear of their designations from the newspaper, as one former Congolese official did after his 2019 listing. Without knowing the steps they can take to get delisted, sanctions targets are not incentivized to change course and cease their destabilizing activities.

Sanctions can also lock in the perception that peaceful relations are impossible with an adversary, even if that adversary has changed significantly since sanctions were imposed. Conflict resolution requires both sides to move beyond their grievances. But sanctions – especially terrorism sanctions – tend to reinforce stigmas, making engagement with hostile parties an even more bitter pill to swallow.

At the far end of the spectrum, sanctions can pave the way toward military action. The Trump administration’s designation of the Iranian Revolutionary Guard Corps as a foreign terrorist organization did not authorize the use of force, but it did condition parts of the U.S. bureaucracy to think of the Guards as terrorists like al-Qaeda. The designation thus led American policymakers to see military means as a legitimate way to counter them.

Why do these measures sometimes have such negative effects, even when they are intended to enhance global peace and stability? A few reasons stand out. If sanctions are intended to bolster Washington’s leverage, then it must be able to adjust them to changing situations. But U.S. sanctions are extremely difficult to change, lift, ease, or understand. Bureaucratic inertia and political pressures are partially to blame. So too is the growing complexity of American sanctions, which are more numerous and based on more legal authorities than ever before. Further, there is no meaningful review process to assess sanctions’ effectiveness in delivering on foreign policy objectives in general, let alone their impacts on conflict prevention.

Members of Congress are often the loudest advocates in Washington for tightening sanctions. Their often-vehement opposition to sanctions relaxation makes sanctions easing extremely politically costly for the executive branch. Also, the sanctions that Congress puts in place by statute can complicate the executive’s efforts to calibrate U.S. economic policy to its other foreign policy goals. For example, while President Obama relaxed sanctions on Cuba in 2016, Congress did not rescind the Helms-Burton Act (1996), which maintained the U.S. embargo on Cuba. While Congress tends to be trigger happy when it comes to imposing sanctions, it falls short in reviewing their effectiveness. As Representative Jim McGovern lamented at a hearing on sanctions in 2022, “In Congress we don’t really talk about these things in any detail.”

To its credit, the Biden administration has taken major steps to address sanctions’ downsides. In the early days of the new presidency, Treasury published a sanctions review proposing policy reforms that drew on recommendations from leading experts. The White House then championed a landmark resolution at the United Nations in 2022 that carved out humanitarian activities from certain Security Council sanctions. The U.S. government then went further, issuing licenses that implemented the UN carveout and extending it to peacebuilding and conflict resolution activities.

But the reforms do not go far enough to address the costs that sanctions pose to peacemaking. With Washington increasingly reliant on sanctions as a tool of foreign policy, addressing these downsides is more pressing than ever.

A good place to start would be setting clear objectives for U.S. sanctions programs and subjecting them to rigorous periodic reviews. This would help U.S. officials to gauge whether sanctions are achieving their goals, and give them the rationale (and the political cover) to change course if the circumstances shift. Both Congress and the executive branch have a role to play in this regard.

Washington should also make clear that peace activities are always permitted, even when sanctions are in place. This may require codifying existing sanctions carveouts into law, and expanding existing sanctions exemptions.

A further important step would be to address private sector concerns about investing in places affected by sanctions so that conflict-affected communities can rebuild. This might be achieved through support for economic regeneration in previously sanctioned countries and strengthened outreach to businesses.

American officials will keep looking to sanctions when navigating the challenges of foreign policy. And they should, if sanctions have a chance of making wars less brutal or bringing them to a close. But without reforms to blunt sanctions’ negative consequences for peacemaking, their effectiveness will be limited. Far greater effort is needed to ensure that this instrument of American power is better deployed in the service of peace and security.