Russia's interest in Syria is obvious. President Bashar al-Assad is a key ally and the country hosts Russia's military presence in the Middle East, but the ongoing conflict in the war-torn country has also served as the perfect proving ground for new military equipment.
Russian aircraft have been in Syrian skies for more than two years, but state-of-the-art platforms like the SU-35 "Flanker" fighter jet and drones have recently joined in. On the ground, brand new Typhoon-M armored vehicles have been seen. The constant conflict in Syria gives Russia the rare opportunity to get see how these new weapons will perform in warfare conditions.
"It's the first time Russians have fought in a conflict outside the confines of the Soviet Bloc since the Soviet Union collapsed in 1991," Jim Phillips, senior research fellow for Middle Eastern affairs at the Heritage Foundation, told me in an interview.
That's a big deal, because it gives Russian forces the opportunity to gain combat experience in Syria's desert conditions. Russian military engineers noted how Syria offers a unique learning opportunity for new platforms in an interview with the Associated Press.
"There are many details that one can't foresee in a factory, because the conditions are basic there. The equipment is new and we use it here several times. Sometimes even minor things like sand can cause a problem," said Kirill Morozov, a Russian military engineer.
Russian fighter jets, bombers, cruise missiles and even some soldiers have all been used in the Syrian conflict since Russia first intervened in September 2015. The timing was almost perfect, considering Russia had just finished building Khmeimim airbase in Latakia province just weeks before starting military operations. Khmeimim has served as the center for Russia's ongoing air operations ever since.
The presence of the SU-35 is as important a learning opportunity for the U.S. as it is for Russia. The SU-35 is Russia's answer to U.S "fifth generation" fighter aircraft like the F-35 and F-22. While the SU-35 is believed to have capabilities similar to last generation U.S. aircraft, it's unclear to all parties if it can hold its own with the new models. Combat experience gained in Syria might help determine what exactly the Flanker can do, even though it isn't fighting U.S. forces.
Missions in Syria will also help Russia continue to develop its drone programs. Russia only started fully integrating drones into its arsenal approximately years ago, and the Syrian combat environment could allow Russia to gain drone experience similar to what the U.S. got in Afghanistan and Iraq.
So should the U.S. be concerned?
"I think the U.S. would be prudent, and it should be watching very closely what the Russians are doing there. Apart from testing equipment, I think almost even more important is the combat experience," said Phillips. "That could be important going into the future."