“The system worked.” That’s how Leslie Gelb famously described U.S. policymaking during the Vietnam War. By this, Gelb meant not that the United States had waged an effective military campaign against its adversaries in Indochina (he believed quite the opposite, calling the war a “quagmire”), but that U.S. strategists had gotten the policy outcome that they wanted. That outcome was a war that was enormously costly and obviously unwinnable but which at least staved off a communist victory in the short-term. Gelb contended that America’s leaders never intended to win the war in Vietnam; they sent tens of thousands of soldiers to their deaths simply so that South Vietnam would not be lost on their watch.

Thirty years later, Samantha Power invoked the same phrase to describe U.S. inaction toward the Rwandan genocide. “The system worked,” she argued, in the sense that America’s policy of nonintervention was not an accident but a deliberate choice by those in power. Decisionmakers in Washington could have opted for an energetic response to the unfolding massacre of more than eight hundred thousand Rwandans if they had so desired. That the Clinton administration did not act was because stopping the atrocities was never a priority. Other policy goals were judged to matter more.

Today, it is fair to say that the system has worked in Syria. This time, however, the blame cannot be placed solely at the feet of faceless bureaucrats and timid politicians in the United States. It is the international system that is at fault.

For throughout seven and a half years of mass slaughter and unspeakable suffering in Syria—as of 2018, over five hundred thousand people have been killed and more than half of Syria’s prewar population has been displaced—the fundamental rules of international society have broadly operated as they are supposed to. What looks like unregulated awfulness is, at least in part, the mostly unsurprising product of an international system that has been designed to serve the interests of powerful states at the expense of the powerless.

International order is not usually regarded as a set of rules that enable the gross mistreatment of civilian populations. The conventional wisdom is that, ever since World War II (and especially after 1991), America and its allies have propagated a common international rulebook that, by and large, has made the world a better, more peaceable, and altogether more civilized place. For a long time, the fear was that authoritarian powers such as China and Russia would upend the liberal order in favor of something less humane. Since the election of Donald Trump, a more prominent worry is that America itself might be the one to tear the liberal rulebook to shreds.

Of course, there are those who argue that the rules-based order was never quite as rules-based or orderly as its proponents like to make out. There is a great deal of truth to these claims. But it would be wrong to dismiss the existence of a rules-based international order altogether. Simply put, there are certain norms and values that the world’s most powerful governments can be observed to hold dear, and which do appear to animate their foreign policies. It is just that these rules do not always privilege the lives and dignity of ordinary people. This dark underbelly of international order has been painfully conspicuous in the case of Syria.

The Syrian Civil War began in March 2011. Within months, regional governments were funding and arming rival groups. Some called for the removal of President Bashar al-Assad, arguing that peace could not be achieved unless the dictator stepped down.

It would be three years, however, before the world’s leading powers saw fit to become involved as active participants in the conflict. In that time, tens of thousands of Syrians were killed by forces loyal to Assad, anti-government rebels, and because of disease and starvation. Yet there was no serious discussion of a military or even a diplomatic intervention to force a ceasefire upon the warring parties. If sovereignty was supposed to impose a “responsibility to protect” upon the Assad regime, it did not—and the international community did not insist upon it.

Indeed, instead of cooperating to impose a pause in hostilities, external powers ramped up their efforts to supply arms and equipment, train local fighters, and share intelligence—all but ensuring that the war would continue to rage. For the outside world, ensuring that the “right side” won in Syria was more important than bringing about a cessation of hostilities. It still is.

The first signs that the United States might use its own firepower in Syria came in August 2013, when Assad’s forces used chemical weapons in rebel-held areas of Damascus. The use of such weapons crossed the so-called “red line” set by President Barack Obama, who duly began to plan for a limited military strike to punish the Syrian government for its crimes. But the intervention never came. Obama could not even muster political support (at home or abroad) for what John Kerry called an “unbelievably small” strike against Assad.

Instead, the United States joined with Russia, a close ally of Assad, to implement an international solution to the problem of Syria’s chemical weapons, resulting in UN Security Council Resolution 2118, which obliged Syria to dismantle its chemical arsenal. This outcome had the advantages of dealing with Assad’s crimes through the fabric of public international law and allowing Obama to claim a diplomatic success. But it also allowed Russia to protect its Syrian ally from an armed attack and gave Assad the green light to continue his war of reconquest. In short, the international system worked: all sides got want they wanted—except, of course, the ordinary civilians who remained vulnerable to the predations of the ruthless Syrian regime.

American armaments began to rain down in Syria the following year, but only once the Islamic State (ISIS) had made vast territorial gains in the region. In the eyes of the West, the rise of ISIS transformed the Syrian war from a humanitarian crisis into a bona fide security threat that could no longer be ignored. Not only did ISIS threaten to topple the U.S.-backed government in neighboring Iraq, but the group also claimed several high-profile terror attacks against Western targets. Faced with such a threat, the United States was galvanized into military action.

Even so, the Obama administration took care not to attack Syrian government positions for fear of provoking conflict with Russia. The U.S.-led intervention was specifically targeted against ISIS. Efforts were made to “deconflict” operations conducted by the United States, Russia, and other intervening parties such as Iran and Turkey. In due course, a situation was worked out whereby external powers would attack the various non-state actors operating inside Syria (ISIS, anti-government rebels) with relative impunity, each tacitly acknowledging that others could and would do the same.

The sovereignty of the Assad government was thus violated but not altogether rejected. No external participant in the Syrian Civil War launched direct, sustained attacks against the sovereign Assad regime. In this sense, Assad’s patrons in Moscow ensured that the rules of the international system stood fast and continued to work in favor of the nominally sovereign government in Damascus.

By the time President Trump came into office in January 2017, it was clear that the international community privileged certain international norms over others when it came to the Syrian crisis. In six years of fighting, external powers had conceded that meddling in Syria’s internal affairs would take place, that chemical weapons usage would be prohibited, but that the sovereignty and survival of the Assad regime would not be challenged. This was the bargain. Nothing meaningful had been done to end the suffering of the Syrian people.

Trump’s two military strikes against the government of Syria are instructive in this regard. In 2017 and 2018, Trump ordered airstrikes against Assad’s military installations with the express purpose of punishing Assad for using chemical weapons. For Trump and his supporters, Assad’s use of chemical weapons was beyond the pale—a barbarous and unlawful act that must be punished by military force. But it is telling that Assad’s other crimes (of which there are many) have never drawn a direct military response from America, its allies, or, indeed, any other external actor. Against Assad, only pinprick missile strikes are possible for as long as he enjoys the backing of Moscow.

This is the stark reality that the Syrian crisis has helped to bring into focus: while international society can agree on the unacceptability of chemical weapons, there is no such intersubjective belief among the world’s governments that action is required to stop half a million civilians from being killed by other means. Mass murders, indiscriminate killing, collective punishments, rapes, starvation, torture—all of these atrocities and more have gone unpunished by the primary stewards of international order because there is no practicable rule for their prevention. It is not necessarily that world leaders do not care about the Syrian people, just that not enough of them have agreed upon a viable set of rules to put the interests of ordinary people first.