Russia has added fighter jets and air defense systems to Ukraine's Crimean peninsula, indicating it is flexing its muscles along the Black Sea.
Defense One cited satellite photos, observers, and officials from U.S. intelligence in reporting the "significant" increase in Russian military assets on the strategically located peninsula.
The images were taken between January 2018 and this past April. Ten air defense systems and Russian fighters are now at various parts of the land mass.
Sarah Bidgood, director of the Eurasia Nonproliferation Program at Middlebury College, told Defense One the military buildup "suggests that Russia is interested in being able to exercise more control over the Black Sea, which then affords them the ability to project power beyond their immediate environment."
"This is a significant buildup," Bidgood added. "NATO is going to be under increasing pressure from allies in the region to show that it's able to push back against Russian attempts to gain greater control of the Black Sea. To me, that's a really dangerous environment."
Russia has conducted military flights near U.S. and other NATO nations' airspace in recent years, and it has sailed spy ships in international waters off the coast of the U.S.
Russia annexed Crimea from Ukraine in 2014, and friction between the two countries continues.