An international investigative team on Wednesday charged four people, including three with ties to Russian intelligence, with shooting down a Malaysia Airlines jet over Ukraine in 2014, killing 298 people.
The long-awaited announcement, the culmination of an investigation by officials from five countries, is the first time anyone has been charged in connection with the deadliest single episode in the five-year civil war in Ukraine.
Moscow has consistently denied any involvement in the disaster, but Western countries and experts have said from the beginning that Russian-backed separatists fighting the Ukrainian government were responsible.
Malaysia Airlines Flight 17 was flying from Amsterdam to Kuala Lumpur, Malaysia, on July 17, 2014, when it was blown out of the sky over eastern Ukraine, where the civil war was raging.
The downing came just four months after an unrelated disaster for the airline, when Flight 370 disappeared en route to Beijing from Kuala Lumpur with 239 people aboard. That plane has never been found.
The debris of Flight 17 indicated that the jet had been brought down by an antiaircraft missile. Five countries that were directly affected by the tragedy — Australia, Belgium, Malaysia, the Netherlands and Ukraine — started a joint investigation.
Almost immediately, evidence pointed to the involvement of Russia, and Western governments concluded that the Kremlin was responsible. Though Moscow denied it at the time, Russia was supplying munitions to rebels in eastern Ukraine, and many Russians were fighting for the separatists there.
Investigators quickly identified the missile as Russian, and photographs and videos showed a launcher for that type of missile being spirited across the border into rebel-held Ukrainian territory, and then back into Russia.
There has been much speculation that the people who fired the missile thought they were aiming at a Ukrainian military plane, not an airliner. The separatists had shot down Ukrainian aircraft before.
Three of the four men accused in the case are Russians believed to be living in Russia, prosecutors said.
One, Igor Girkin, is a former colonel in the F.S.B., Russia’s domestic security service. In 2014, he was the minister of defense for the self-proclaimed Donetsk People’s Republic, one of the breakaway regions in eastern Ukraine.
Sergey Dubinsky and Oleg Pulatov worked under Mr. Girkin in 2014 and had been agents of the G.R.U., the Russian military intelligence agency implicated in the interference in the 2016 United States election, and the nerve agent attack on a Russian former spy in Britain.
The fourth suspect, Leonid Kharchenko, is a Ukrainian who led a separatist combat unit. The investigators said they did not know his location, though they believe he is probably in the breakaway territory.
President Vladimir V. Putin’s government had friendly relations with Ukraine when there was a pro-Russia government in Kiev.
That changed dramatically when mass protests prompted the Ukranian president, Viktor F. Yanukovych, to flee to Russia in February 2014. The newly ascendant faction wanted to distance the country from Mr. Putin’s influence and embrace the West, possibly even joining the European Union and NATO.
Days after Mr. Yanukovych was ousted, Russian troops poured into Crimea, a region in eastern Ukraine. The Kremlin first denied that the forces were Russian, then admitted it and annexed Crimea.
The fighting began in eastern Ukraine a few weeks later, and it continues to this day, a constant threat to Ukrainian prosperity and political stability.
Despite the painstaking work by investigators, probably not much.
The investigators decided to file charges in a Dutch court, and said the trial would begin on March 9, 2020. They are highly likely to present more evidence as time goes on.
But with the suspects on Russian soil and effectively under Mr. Putin’s protection, they are unlikely to appear to answer the charges.