Smoke rises from the detonation of the 2,000-year-old temple of Baalshamin in Palmyra, Syria. (Associated Press)

THE SCALE of destruction in Syria’s four-year-old uprising is so vast, and the extent of carnage and suffering so appalling, that individual massacres and acts of devastation are easily lost in the barrage of daily news. As Stalin is supposed to have said: A single death is a tragedy; a million deaths is a statistic.

Still, it’s worth taking account of the recent detonation of an archeological jewel, the Baalshamin Temple in the ancient city of Palmyra, by Islamic State militants. The destruction of the 2,000-year-old temple , which stood amid one of the Middle East’s most dazzlingly beautiful sites of antiquity, was a useful reminder of the war’s ongoing wanton destruction — and of the abiding indifference of Western governments.

The temple, once thronged by camera-toting tourists, was blown up in broad daylight by the Islamic State, which seized the city from government forces a few months ago. Like other archeological treasures, statues and sanctuaries throughout Syria and Iraq, it was regarded by the Islamic State as idolatrous and therefore a candidate for looting, sledgehammering and obliteration.

The Islamic State is hardly alone in laying waste to Syria’s unfathomably rich cultural heritage; other rebel groups, as well as the government of Bashar al-Assad itself, have taken part in the shelling, bombing and destruction of dozens of archeological sites when it met their military or ideological needs.

The group’s goal is not only the destruction of idols and false gods but also the display of impunity as a demonstration of power and purpose. The Islamic State murders and destroys because it can and because no other power has mustered the will and resources to stand up to it. In its propaganda, that has proven an effective message with special appeal to the movement’s young recruits.

What’s being destroyed in Syria, and in war-torn provinces of Iraq as well, is the past, and historical memory itself. The ancient world’s antiquities and breathtaking ruins are literally irreplaceable, their loss irreversible.

The devoted caretakers who have watched over those sites have been painfully aware of that, few more so than Khaled al-Assad, the retired director of antiquities at Palmyra, who was in his early 80s. He was beheaded by the Islamic State last week, allegedly for the “crimes” of having not divulged to militants the location of priceless artifacts from the city’s ruins and for having rubbed shoulders with Western “infidels” at overseas archeological conferences. A historian who had written many books about Palmyra’s riches, his body was hung from a city lamppost.

The detonation of a single temple and the decapitation of a single scholar merit a few headlines. The ongoing human tragedy is constant and all but unnoticed. So many war crimes have been committed by so many parties in Syria that it becomes easy to lose track of the toll.

The destruction of Palmyra is a war crime. So is the Assad government’s indiscriminate deployment of “barrel bombs” in civilian areas and its repeated use of chlorine gas — attacks that have accelerated the displacement of more than 11 million people, about half of Syria’s pre-war population, 4 million of whom have fled to other countries.

Through it all, Western governments, led by the Obama administration, have shied away from any decisive action.