Shannon P. Carcelli

International Affairs
Jul 18 · 7 min read
President Donald J. Trump delivers his State of the Union address at the US Capitol, Tuesday, Feb. 5, 2019, in Washington, DC. Image credit: Official White House Photo by Shealah Craighead via Flickr

Signalling in international relations is defined as ‘the purposive and strategic revealing of information about intent, resolve, and/or capabilities’ to change another country’s behaviour. For example, winning a battle can show a country’s intent, resolve and capabilities and may convince an opponent to negotiate a peace deal. Unfortunately, battles cost both lives and money. If possible, countries prefer to signal their ability to win a war without actually having to go to war. This leads to a dilemma: how can a country show that it is willing to pay the costs to win a war, without actually starting a war? One potential but controversial solution is economic sanctions.

Some scholars are hesitant about the ability of sanctions to serve as effective signals. Threatening sanctions is considered ‘cheap talk’, because anyone could make those threats, whether they truly intended to escalate them or not. Countries must take a more costly action, this thinking goes, to show that they would be willing to pay the costs of war. Such costly actions can be personal — for example, by making promises that a leader cannot break without angering voters — or they can be shared, such as publicly deploying troops to a border as a show of strength. In contrast, cheap talk does little to distinguish a threat as meaningful. Every country in the world could simply make the same idle threat, whether they seriously intended to follow through or not. The point of signalling is to distinguish oneself from the herd and the United States is particularly good at demonstrating its threats of sanctions are serious.

This is as certain attributes of the sanctioning party can help make signals more powerful. Without even trying, the United States can send strong signals simply because of how its political system is set up. Specifically, democratic institutions make it easier to send a strong signal and separate a country from its less resolved counterparts. This is because democratic institutions make it harder to bluff and pretend to have intentions one does not. There are three main reasons that the US might be effective at sending signals through what would normally be considered cheap talk.

Audience costs

First, democratic leaders face the prospect of losing power if they break their promises or back off their threats. Thus domestic audience — that is, voters — might create the costs necessary for a signal to be believed. Some say that democracy maximizes the probability of a leader losing power, due to regular elections and a free press. This can be taken by foreign leaders as evidence that the country is not bluffing. When elections make lying costlier, they tie a leader’s hands and makes them more likely to follow through on a threat.

However, this argument has its detractors. Some scholars claim that democratic leaders are no more likely to be pushed out of office for breaking promises than autocrats. After all, the existence of coups shows that many types of dictators face their own version of an electorate. Other scholars have argued that it is difficult in practice to see leaders being punished at all. A skilled politician can often talk back a statement and there are few cases where a leader has actually lost power for backing down on a threat. The more a leader can stake their reputation on a threat, the stronger a signal that threat will bestow. Unfortunately, it is often difficult to convince politicians to stake their reputation on anything.

Division of Powers

The second reason the US’ sanctions may be particularly effective involves the division of powers within the US government. This is as, in the US, there are multiple centres of power. Interbranch agreement sends a stronger signal than if, say, one leader makes such a threat. Helen Milner shows that this is what leads democracies, such as the US, to be more believable in the promises they make. Essentially, it is harder to bluff when there is a competing branch of government looking over one’s shoulder.

Moreover, even when the branches disagree, the US transmits valuable information of its true intent. One of the most famous examples of sanction success shows this mechanism in action. In 1985, the Reagan administration developed a policy of ‘constructive engagement’ with South Africa over apartheid, with no intention of harming relations by threatening or imposing sanctions. In many political systems, this would be the end of the story. The US would effectively be signalling a lack of interest in apartheid. However, the existence of an independent legislature allowed the US to send a separate signal. In 1986, US Congress passed a bill issuing strong sanctions against South Africa. When President Ronald Reagan vetoed the bill, Congress was able to override the veto. These actions sent strong signal of US resolve as, instead of taking the president’s word for it, South Africa had detailed information on who in the US was willing to push this policy preference, learning that two-thirds of Congress was resolved. This strong congressional signal played a part in ending apartheid.

Lisa Martin’s work bears this out even further. She shows that sanctions that come out of Congress are more lasting and more reliable than executive orders. This is because the more difficult it is to issue a sanction, the stronger the signal that sanction will send. It is more difficult for Congress to get something done, therefore, Congress will be the most effective actor in creating sanctions. This means that the interbranch agreement and disagreement — because of the nature of the US’ political system — make the US particularly good at sending signals through sanctions.

Free press and opposition

A third, and similar, rationale comes from Kenneth Schultz. He argues that domestic opposition is really what leads democracies to send stronger international signals. Regardless of the partisanship of Congress, there will always be a party in opposition and the attitude of the opposition party will show other countries what the US government is really thinking. If the opposition party agrees with the premise of a sanction threat, the threat becomes more serious — the same goes for the press. These are thus useful ways to honestly signal the US’ resolve and increases the ability of sanctions to work as signals. The more the two parties can agree on a sanction, the more powerful that sanction’s signal will be. Once again, US institutions make it more difficult to bluff and demonstrate why the US is well placed to make sanctions credible threats.

What we don’t know: differences between agencies

Next to this, there is potentially another reason why the US is well placed to signal its intent through sanctions. This has to do with the US’ bureaucracy — something which future work on trade sanctions should consider. Much of the sanctions literature to date has treated the executive branch as a monolith, as if every agency within the US government were the same. However, as any government worker knows, that is simply not the case. Several agencies collect their own sanctions lists, for various reasons, and certain agencies within the US government are almost certainly more effective at signalling than others.

Characteristics of different agencies within the executive branch should follow the same logic as the interbranch variation: the bureaucracies that have stricter requirements for issuing sanctions should serve as stronger signals than bureaucracies that do not. For example, the US Federal Maritime Commission is a relatively independent agency and, in the past, has enjoyed some latitude in making sanctions. This should therefore serve as a relatively weak signal. On the other hand, if the US Department of State — which has a direct path to the executive and many congressional reporting requirements — approves sanctions. This should, theoretically, make it clear to the intended target of a sanction that this is a signal that needs to be taken seriously. However, a lack of data and research leaves this an unanswered question. Policy-makers and researchers should work to better understand how bureaucracies craft sanctions, and how effective those sanctions are.


The efficacy of sanctions thus depends not only on what is being signalled but also on who is sending the signal. It is clear that it has a substantial impact whether it is the US Congress, the president, the press or the opposition party — or even all of them — supporting a sanction. However, when it comes to the different agencies of the US bureaucracy and whether their signals should be interpreted differently, it becomes apparent that further work is needed. Despite this, the US is clearly well positioned to send signals on sanctions that are more than simply cheap talk.

Shannon P. Carcelli is an assistant professor in the Department of Government and Politics at the University of Maryland, College Park.

This blogpost is part of a new series, New Policy Perspectives, a collaboration between International Affairs and the Bridging the Gap Project.

The contributions to this series are based on presentations given as part of Bridging the Gap’s New Voices in National Security program.

New Voices in National Security, the newest program by the Bridging the Gap Project, extends current national security debates by incorporating the most up-to-date research findings from both established and emerging scholars who are not typically part of the Washington DC policy orbit. Made possible through support from the Frankel Family Foundation, the workshops are aimed to build connections between innovative national security scholars and members of the policy community, and result in a tailored outreach strategy aimed at informing sound national security decisions.

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