Four years ago, civil unrest began in Syria against the despotic rule of Bashar Assad. After more than 40 years of rule by the Assad clan and in the wake of Arab Spring protests happening elsewhere in the Middle East, Syria’s people began to make their voices heard. The brutal and corrupt regime responded with violence and what followed was a civil war that has, to date, cost the lives of more than 200,000 persons and made millions homeless. The toll of this catastrophe was aptly illustrated in a New York Times graphic feature, “Syria After Four Years of Mayhem.” But what isn’t noted there is that much of this heartbreak might have been averted had the West done something to stop Assad from making war on his own people before the war escalated to the current level of chaos. Though President Obama condemned the violence in Syria, called on Assad to go, and even warned that his use of chemical weapons would cross a “red line” that would force the United States to act, the administration did nothing. As much as this anniversary should cause us to mourn the dead, it should also be noted as a disgrace that stands as an apt symbol of the failure of Obama’s foreign policy.

The graphic illustrates the toll the war has taken on that tortured country. Most dramatic is its depiction of satellite photos that illustrate the collapse of Syria’s population centers. The photos show that Syria is 83 percent darker at night than it was before the start of the war. Sir Edward Gray’s famous comment at the start of World War One that, “The lamps are going out all over Europe. We shall not see them lit again in our lifetime,” seems apt for Syria as well. The war has caused an exodus of epic proportions. Approximately 7.6 million people have been displaced inside of Syria as a result of the fight. But 3.9 million, approximately half of them children, have been forced out of the country and are living as refugees elsewhere in great squalor and suffering.

Also depicted is the current division of the country between armed forces loyal to the government, ISIS, and moderate rebels. But those maps don’t tell the full story either of how the current situation came to be or what is really going on today.

The weakest of the three sides in this civil war are the non-ISIS rebels. Some are genuine moderates. Others are connected to al-Qaeda. Meanwhile the pro-government areas are as likely to contain Lebanese Hezbollah terrorists with a sprinkling of Iranian volunteers as they are Assad’s Alawite base of support within the pre-war Syrian army.

But that current division couldn’t have come about had President Obama not played Hamlet on Syria for two years as the original more moderate rebel forces came to be either dominated or pushed aside by more radical elements tied to al-Qaeda. Even more to the point, it was the vacuum created by the West’s indecision as well as the administration’s fateful decision to pull completely out of Iraq that allowed ISIS to arise while Obama was trying to decide what to do.

Four years later, it’s probably too late to expect Syrian moderates now getting some minimal Western aid to do much about an Assad regime that was backed to the hilt by its Iranian ally and their Lebanese auxiliaries. Even worse, the real explanation for American hesitancy to do something about Syria might have been the president’s desire for a rapprochement with Iran.

It is true that any decision to act on Syria would have been fraught with danger. Intervention in Iraq created a host of unintended consequences—such as the strengthening of Iran—which Americans now regret. There was no guarantee that action would not have created other problems and exposed American forces to terror attacks. But we do know what happened because President Obama either couldn’t make up his mind or was too intent on making nice with Iran to act decisively. Could the fallout from a decision to oust Assad before Iran could rescue him or ISIS arose have resulted in more casualties or refugees? Could the strategic situation have been any worse than the one in which ISIS now controls much of the country while the U.S. has been forced into a tacit alliance with the Islamist despots of Tehran and the butcher of Damascus in order to hold them back?

The debate about the answers to these questions will interest historians in future generations. But for now, all we need to know is that the greatest human-rights catastrophe since Barack Obama became president might well have been averted or at least lessened by decisive American leadership. Along with his many other failures and mistakes, this horror should never be forgotten or be allowed to be obscured as the president’s fans seek to celebrate him. Such a disgrace isn’t merely a bad political choice; it’s a permanent commitment to infamy.