It is the central question of the continuing civil war in Ukraine: to what degree is Russia supplying the weapons that are helping antigovernment forces sustain their secessionist movement? That question became even more relevant this week with the news that NATO’s military commander now supports providing defensive weapons to the Ukraine government.

A recent report on the weapons and military vehicles used in the Ukraine conflict provides evidence for both sides of the argument.

Released late last year by the research company Armament Research Services, or ARES, the report cites several examples of cross-border matériel support to separatists and rebels fighting the government in Kiev. Certain items the researchers came across gave their team pause, as these weapons had been introduced into service only after the 1991 fall of the Soviet Union or had never been documented outside the countries that developed them.

Nic R. Jenzen-Jones, the director of ARES, was able to positively identify 20 weapons systems in Ukraine that had never previously been exported from their country of origin. Nineteen of those came from Russia, and one was from Poland. He calls these “flag items” because they can be clearly tied to outside nations.

From Russia, ARES identified exotic killing tools like the VSS suppressed marksman rifle, heavy armor like the T-72B3 main battle tank, and newer thermobaric rocket launchers like the MRO-A that have not been seen outside the Federation’s borders.

The lone Polish flag item was the PPZR Grom man-portable air defense missile system, which ARES spotted in a YouTube video released by the Ukrainian military. The missile was manufactured in 2007, according to markings painted on its exterior.

But the report also draws conclusions that counter the widely accepted narrative that the insurgents depend on Russian matériel.

By analyzing photographs of captured ordnance, ARES also determined that existing stockpiles of weapons were the single biggest source of military goods used by pro-Russian separatists in eastern Ukraine.

Most of these weapons were unremarkable from a proliferation standpoint. Fighters on both sides carried older Kalashnikov AK-47 type assault rifles as well as relatively newer AK-74 variants of the AK-74 line first introduced by the Red Army 40 years ago. Most machine guns, artillery pieces, and armored fighting vehicles that ARES documented were similarly traceable to what was already in Ukrainian hands before the revolution.

To write these reports, ARES scoured open-source media, picking up militarily significant data from photos taken by journalists, field researchers and local sources across Ukraine.

Mr. Jenzen-Jones, of Perth, Australia, who founded the firm in January 2014, has assembled a team of specialists in the United Kingdom, United States and Germany, supported by researchers in Russia, Lebanon, Libya and elsewhere. Their services — including arms research, analysis and training — were once the province of state intelligence agencies.

Previously, a report of this quality and depth would have been, for the American government, a collaboration between multiple offices of the National Ground Intelligence Center in Charlottesville, Va. and the Defense Intelligence Agency in Washington, D.C.

“We’re well positioned to support smaller organizations which may not have these sorts of weapons technical intelligence capabilities in-house, or who may not have access to some of the sources, actors, or regions which we do,” Mr. Jenzen-Jones said.

Mr. Jenzen-Jones co-authored the Ukraine report with another ARES technical specialist, Jonathan Ferguson, who is also the Curator of Firearms at the National Firearms Centre at the Royal Armouries Museum in Leeds, U.K. Together they identified more than 100 separate weapons systems used on all side of the Ukraine conflict, using more than 60 different munition types and employing 70-plus different models of armored fighting vehicles and tanks.

One point the report emphasizes is that these items often changed hands several times throughout the conflict, as weapons and vehicles were captured and recaptured by various armed factions.

The positive identification of munitions and weapons systems requires keen attention to detail. Mr. Jenzen-Jones and Mr. Ferguson note that mistakes are easy to make when two items look so similar, and cites one particular machine gun as a useful example.

Photo

The NSV is a heavy machine gun fielded before the dissolution of the Soviet Union, and they were in use by the Ukrainian military before the recent fighting began. Its receiver is heavily riveted as shown in the red ovals in the photograph above.

The newer Kord heavy machine gun appears very similar to the NSV, but a practiced eye can spot the lack of rivets in the receiver that are just one of the features setting it apart from the NSV. The Kord was made by the Russian Federation after 1991, and had not been in the Ukrainian arsenal.

Of the two, only the NSV was positively identified in Ukraine, according to ARES. But at least one website mistakenly identified an NSV as a Kord and thus erroneously claimed that the weapons had been shipped from elements within the Russian Federation to insurgents across the border.

As Mr. Jenzen-Jones noted, these are minor examples of a complex discipline. “The differential identification of arms and munitions can range from the reassuringly simple to the absurdly difficult,” he said. “Many people dedicate their lives to becoming subject matter experts in incredibly narrow fields of expertise.”

John Ismay is a former Navy explosive ordnance disposal officer and a 2014 graduate of the Columbia University Graduate School of Journalism.