While the war in Ukraine is proving costly for both sides, the ability for Russia to replenish munitions and military hardware on its own leaves an open question about how much longer the conflict can go on.

"They are running low on everything," Eliot Cohen, chair in strategy at the Washington, D.C.-based bipartisan Center for Strategic and International Studies, told The Wall Street Journal about the Russian war effort.

According to the report, while Ukraine is getting billions in aid and equipment from the United States and some NATO allies, Russia must rely on its own economy to sustain the military action.

Thanks to Western backing with money and arms, Ukraine has been able to exact a huge cost to Russian President Vladimir Putin, causing supply shortages that go back to early summer.

Reuters reported in June that Russia was already experiencing a shortage of drones, night vision equipment, food, diesel fuel, and other items needed by troops in the combat zone.

"We urgently need to obtain at least 3 drones like these before Saturday for our police special forces," one administrator in a Telegram chat, who used the name Ruslana, posted on April 12. "They are badly needed and could save the lives of lots of our guys."

Since then, Russian troops have had to pull back from several areas in Ukraine after suffering heavy casualties and equipment losses imposed by Ukrainian forces.

The New York Times reported in October that Western sanctions against Russia have damaged its defense industry while the Russian military has lost an estimated 6,000 pieces of equipment since the war started in February.

According to the report, the sanctions are making it harder for Russia to replace supplies needed to repair diesel engines, helicopters, and planes.

The restrictions are also hampering Russia from building more precision weapons, the report said.

Defense News reported Nov. 14 that more people and firms supporting the Russians were added to the sanctions list to further stall military support.

"Businesses worldwide are advised to do their due diligence in order to avoid being targeted for sanctions," Secretary of State Antony Blinken said in a statement at the time. He said the U.S. "will continue to crack down on Russia's attempts to evade international sanctions to fund its war machine."

The wild card in the mix, however, is how much help Russia can get from its ally Iran.

According to the Journal's report, Iranian suicide drones are increasingly turning up on the battlefield and have had a "significant impact" in the fighting.

Tehran has agreed to supply Putin with two different ballistic missile systems with ranges of between 180-430 miles respectively, the Journal's report said.

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