On April 4, Syrian government forces launched a chemical weapons attack against the town of Khan Shaykhun, killing dozens of people, including several children. Two days later, the United States struck the Syrian government’s Shayrat airfield with cruise missiles, killing at least seven people and destroying a number of Syrian warplanes. Soon after the strike, U.S. Senators John McCain and Lindsey Graham released a joint statement praising President Donald Trump’s decision to “sen[d] an important message” to the Syrian regime—a sentiment that many other observers have since echoed.

But what message, exactly, did the strikes send? Many of the attack’s proponents have argued that it will show Syrian President Bashar al-Assad that the United States will punish his government if it uses chemical weapons again, and that this will deter it from choosing to do so. In fact, the strike’s message was ambiguous—and so it is misguided to assume that the attack will shape Assad’s behavior.

A civil defense member breathing through an oxygen mask after the gas attack in Khan Shaykhun, Syria, April 2017. Ammar Abdullah / REUTERS

MIXED MESSAGES

There are three main ways that Assad might have interpreted the U.S. strike. In the first scenario, Assad takes the attack as a signal that the United States is serious about its commitment to using additional force in response to chemical weapons attacks. If this is how Assad views the strike, then the Syrian president would probably keep his forces from using chemical weapons again out of fear of U.S. retaliation. From the point of view of the United States, this is the most optimistic scenario, and the one that offers the most bang for the buck: a shift in Assad’s behavior in exchange for only 59 Tomahawk missiles.

In the second scenario, Assad sees the strike as a signal that the United States doesn’t much care about his regime’s use of chemical weapons. In response to an act that governments around the world consider among the worst of all war crimes, the United States merely launched a few dozen cruise missiles at an airfield, giving Assad the chance to protect his forces by telling his Russian patrons in advance that the strikes were coming. If the United States really cared about chemical weapons attacks as much as it claims, this logic goes, then it would have done far more to change Assad’s calculus. Thinking this way, Assad would have no reason to change his approach to the use of chemical weapons—particularly if he believes that there are no substitutes for them in Syria’s civil conflict. He would expect that using them again would incur only another slap on the wrist.

When the United States sends military signals that are cheap to execute, the targets do not take Washington’s threats about its future intentions seriously.

Then there is the third possibility—that Assad believes that Trump ordered the strike as a domestic political play, meant to show the American public that Washington is willing to take action in the face of what Trump called an “affront to humanity.” In this reading, the strike was not intended to communicate anything about the United States’ future resolve to act against Syria; instead, it was mostly a performance for the American people. If Assad believes that this was the primary motivation for the strike, then he would have little reason to change his previous assessments of how the United States might treat him in the future.

Each of these interpretations of the strike would have different implications for how Assad behaves. The strike sent an ambiguous signal about how the United States evaluated the chemical weapons attack, and it did not clarify how the United States would respond to similar actions in the future.

The U.S. Navy guided-missile destroyer USS Ross firing a Tomahawk missile in the Mediterranean Sea, April 2017. Robert S. Price / Courtesy U.S. Navy / Handout via REUTERS

BETTING LOW

The reason for this ambiguity is simple: when the United States sends military signals that are cheap to execute—for example, by launching cruise missiles or ordering drone strikes—the targets do not take Washington’s threats about its future intentions seriously. This holds true even when the United States threatens to use force against weak states, such as Syria.

Consider the logic in terms of the game of poker. As a hand progresses, players make bets to try to influence their opponents’ beliefs about the cards they hold. A player goes “all in” when she puts all of her chips into the pot. This player’s willingness to risk everything is usually interpreted as a signal that she has a strong hand, since she would probably lose everything by making such a bet without good cards. By contrast, a player who tosses the minimum bet into the pot will not convince his opponents that he has a strong hand. It’s possible that such a minimum-bet player has good cards and is simply waiting to bet more later in the game, but the cheap bet risks very little of the player’s chips, so it doesn’t signal to the other players that he is holding good cards.

A similar logic applies to the United States’ strike against Syria, although in this case, the strike is a signal of the United States’ willingness to use force. The attack on the airfield was easy and inexpensive. Cruise missiles are extremely cheap relative to the hundreds of billions of dollars that Washington spends on defense each year, and the United States carried out the strike without endangering any of its own troops. In these ways, the strike bore all the hallmarks of the model of force that Washington has developed since the end of the Cold War: operations that target weak adversaries from a distance, with few or no U.S. forces on the ground.

Because these kinds of attacks are cheap, easy, and do not generate a lot of U.S. casualties, the American public is usually willing to tolerate them. But that is also why such attacks do not signal to the United States’ adversaries that Washington is resolved to go much further. In other words, no one is fooled into thinking that the United States is willing to go “all in” when it places a small bet by launching a few missiles. This explains why the United States has long struggled to make weak states such as Iraq, Libya, and Syria change their behavior using cheap force.

The Trump administration would be mistaken to conclude that its recent strike has convinced the Syrian regime that the United States is resolved to act in the face of future chemical weapons use—or indeed, that the United States will escalate its involvement in the civil war more generally. (This doesn’t mean that the Trump administration should launch additional bombing raids against Assad to show that it means business: the limited nature of the recent strike may be an accurate indication that the United States is not very committed to ending the war in Syria.) Nor should the administration assume that the recent attack will deter other countries from misbehaving. If this strike cannot convince its target to rein in his use of violence against civilians, then Washington should not expect it to convince anyone else—in Iran or North Korea, for example—to change their behavior, either.