WASHINGTON -- Newly published satellite photographs suggest that Russia has rebuilt a weapons storage bunker in its Baltic Sea exclave of Kaliningrad, suggesting that Moscow could be considering placing nuclear weapons there, according to a U.S. think tank.
The photographs, published on June 18 by the Federation of American Scientists, were the latest source of concern for Western military observers about Russia's capabilities in the region wedged between Lithuania and Poland that is home to Russia's Baltic Fleet.
Hans Kristensen, a respected nuclear expert and director of the federation's nuclear information project, said the images showed the weapons bunker, located about 50 kilometers from the Polish border, had been under major renovation since 2016.
"It is to my knowledge the only nuclear weapons storage site in the Kaliningrad region," he wrote.
"The latest upgrade obviously raises questions about what the operational status of the site is," he said. "The satellite images do not provide conclusive answers to these questions."
According to Kristensen, Russia's publicly stated policy is that so-called "nonstrategic weapon systems" -- essentially small, short-range battlefield weapons -- are stored in a central facility within Russia's main borders. The renovation of the Kaliningrad site, at Kulikovo, means it could be supplied with such warheads during a crisis.
Kristensen said it was unclear whether there were nuclear warheads already on site or if Russia is preparing to move them there -- a move that would drastically increase tensions with NATO. Alternately, the facility may be being upgraded so that nuclear weapons could be moved in at short notice.
Kaliningrad's location makes it particularly problematic for NATO military planners. Even short-range weaponry based in the region could put NATO-member cities like Warsaw or even Berlin at risk.
In late January, the top missile commander for the Kaliningrad region, Colonel Gordetsky, said that engineers had finished building the necessary infrastructure to host the advanced Iskander-M ballistic-missile system. Days later, Vladimir Shamanov, a former military commander who now heads the Defense Committee in Russia's lower house of parliament, echoed that remark, and said Iskander-M systems had, in fact, been deployed. Lithuania's defense minister also confirmed the deployment.
U.S. and NATO officials have said the location of such missile systems is destabilizing.