With help from Russia and Palestinian militants in Syria, the body of Israel Defense Forces Sgt. First Class Zachary Baumel has been found at a Palestinian refugee camp and returned home after 37 years of searching.

Baumel, 21, is believed to have died in the tank battle of Sultan Yacoub during the First Lebanon War, in which more than 20 Israeli servicemen were killed.

That day in 1982 led his family and the nation he was fighting for on a decadeslong quest to find out what happened. There had been speculation that Baumel was still alive and had been taken prisoner alongside fellow servicemen Tzvi Feldman and Yehuda Katz.

Baumel’s parents made the search an international pressure campaign. His father died a decade ago, but his 90-year-old mother Miriam now has some closure in the fate of her lost son, a dual Israeli-American citizen who was born in Brooklyn, New York, but emigrated to Israel, where he joined the IDF.

In 1993, Palestinian Liberation Organization leader Yasser Arafat gave part of the soldier’s dog tag to Israeli Prime Minister Yitzhak Rabin, although Arafat claimed he didn’t know the location of Baumel’s body.

The return of Baumel’s remains finally came with Operation Bittersweet Song, a two-year IDF mission to recover lost soldiers from territory in Syria controlled by the Islamic State.

The mission is steeped in mystery, but it involved odd bedfellows united in the quest to return Baumel’s remains to his family. An official from a Palestinian terrorist organization said armed factions recovered the body outside the Yarmouk refugee camp near the Syrian capital, Damascus, along with the remains of at least 10 other unidentified people. Those remains have not turned up a match to Feldman or Katz. The pro-Syrian-regime terrorist group, the Popular Front for the Liberation of Palestine, is one of several operating from Yarmouk.

Former Israeli Defense Minister Avigdor Lieberman initiated the operation that coordinated with Moscow, a close ally of Syrian dictator Bashar Assad, to search for the remains as ISIS retreated from land it had seized in Syria in the power vacuum created by the country's civil war.

After a diplomatic row last September between Israel and Russia, a defensive Kremlin announced that it had been helping Israel search for the remains of lost soldiers, a claim the Israeli military refused to comment on. Moscow said one Russian soldier had been injured in the mission.

This week, two years after its inception, Operation Bittersweet Song produced results.

“We want all IDF soldiers to know that when they enlist, the State of Israel will do everything it takes if they — heaven forbid — fall captive or go missing, in order to bring them home,” Lt. Col. Nir Israeli, head of IDF's missing soldiers unit, said Wednesday.

“This is a repayment of a moral debt to the fallen soldiers of the IDF, a repayment of a moral debt to their families,” Israeli Prime Minister Benjamin Netanyahu said. He called the news “one of the most moving moments in all my years as prime minister.”

Netanyahu appeared at a joint press conference with Russian President Vladimir Putin on Thursday, acknowledging Russia's assistance for the first time. In a ceremony in Moscow, Russia gave Israel Baumel's remains, along with his tzitzit ritual fringes and the jumpsuit and military boots he died wearing, in a coffin covered by the Israeli flag.

“As you may know, our military personnel and their Syrian partners helped find Zachary’s remains. We are glad that he will receive proper military honors in his homeland,” Putin said. “Another, purely humanitarian aspect of this case is that Zachary’s family will be able to bring flowers to his grave.”

The Syrian government denied Putin's assertion that its military had been involved in the operation. “Syria has no clue about the Israeli soldier’s remains,” read a statement released on the state-run SANA news agency Thursday. It claimed that “what has happened is new evidence confirming cooperation between terrorist groups” and Israeli intelligence. Syria and Israel have been in a state of war since Israel's establishment.

Baumel was buried in Jerusalem's Mount Herzl military cemetery Thursday night.

Israeli is still looking to locate Feldman and Katz. Feldman was a crewman in the same tank as Baumel, and Katz served in a tank that was attacked just over a mile away.

Katz’s sister told Israel's Channel 12 that despite the long odds she still believes her brother might have been captured during the battle and stayed alive. “We aren’t losing hope and even, though it seems unreasonable, still hope he’s alive,” she said.