The Arab Economic and Social Development summit, part of the Arab League, is hardly the sort of event that regularly makes headlines. This year, however, the summit is being held in Lebanon, and has been overshadowed by events that happened more than four decades ago.

Lebanese society is going through a moment of upheaval. There has not been a government since elections last May. For months, protests and demonstrations have roiled the country, as discontent at the lack of political progress and a stagnating economy has spilled on to the streets. On Sunday, the same day the summit began, as many as 20,000 people took to the streets to demand change.

With so much happening, it is extraordinary that the disappearance of an Iranian-Lebanese cleric in 1978 has overshadowed the summit and forced the Libyan delegation to cancel its attendance. But the disappearance of Imam Musa al-Sadr is no mere political mystery. It is a historical event that is still relevant to the Middle East today. The ghosts of the past, in Lebanon as elsewhere in the region, still affect the living.

Musa al-Sadr was a Shiite cleric who was heavily involved in Lebanese politics. In the febrile atmosphere of 1970s Lebanon, he founded a movement to reform the political system and give more representation to the Shiite community. That movement, which grew into the political party Amal, currently the largest Shiite political party in parliament, became increasingly important after the Lebanese civil war started in 1975.

But in 1978, on a trip to Libya at the invitation of Muammar Gaddafi, Sadr and two of his companions disappeared. The Libyan government denied responsibility and the mystery has never been resolved.

Long-buried tensions over the disappearance returned last week when Nabih Berri, the highest-ranking Shiite politician in Lebanon and the head of Amal, said Libya should not participate in the summit. Other members of the party warned that any Libyan delegation would not be allowed through the airport.

After small protests were staged in both countries, Libya’s foreign minister confirmed that the country would not send a delegation.

That Sadr still has such a pull on the Lebanese imagination is testament to the fact that his disappearance wasn’t merely the vanishing of a prominent political and intellectual figure. It came at a moment when Shiite Islam was rising as a political and religious force.

In Lebanon in the 1970s, Sadr was instrumental in galvanizing a previously marginalized community into political action.

In Iran, civil resistance to the Shah had taken on a distinctively religious dimension. All through 1978, the same year Sadr vanished, there were protests and strikes across Iran. The end of the monarchy and the beginning of Iran’s Islamic Revolution were mere months away.

What changed in the 1970s was a rising consciousness of Shiite political, as opposed to merely religious, power. The Iranian revolution put the weight of a government behind those ideas, and set off a tussle between Iraq and Iran, and between an expansionist Iran and Saudi Arabia, that endures to this day.

Who was responsible for Sadr’s disappearance is a question that has plagued the Shiite community for decades

Who was responsible for Sadr’s disappearance is a question that has plagued the Shiite community for decades.

The belief that Gaddafi had something to do it has never gone away. But in truth, many factions could also have had reasons to eliminate Sadr: his rising power in the Shiite community worried many established Lebanese leaders; he antagonized the Palestine Liberation Organization and Yasser Arafat; the Syrian leadership, which had immense influence across Lebanon, may have disliked a rising star. Some even point the finger at Ayatollah Ruhollah Khomeini, then in exile in Iraq.

Nor has the story ended. After the fall of the Gaddafi regime in 2011, one of his sons, Hannibal, who had held only minor roles in the Libyan government, ended up in Damascus, from where he was lured in 2015, allegedly by members of Amal, to Lebanon, where he was imprisoned and forced to make a video requesting that anyone with information on the disappearance of Sadr come forward.

The Lebanese police released him from captivity, only to re-arrest him in connection with the case. He is currently imprisoned in Beirut, ostensibly awaiting trial, but more likely as a bargaining chip with the Gaddafi family.

The story of Musa al-Sadr highlights how tangled the recent history of the Middle East can be. Events from what seem a long time ago still matter, partly because many of the personalities are still around, but mainly because those events still affect daily politics.

Sadr was at the heart of rising Shiite political influence in Lebanon and Iran. That influence has only increased in the intervening decades and is felt from the domestic politics of Lebanon, to the war in Syria, to the conflicts in Iraq, to the tensions between Iran and the Arab Gulf states.

The history of what happened to Musa al-Sadr is anything but past.

This article was provided to Asia Times by Syndication Bureau, which holds copyright.