Valentin Danilov, 83, is a former executive officer on a Soviet sub who proudly wears his old Soviet military uniform. Crimeans like Danilov have, without changing their residence, lived in three different countries in the past 25 years — the Soviet Union, then Ukraine and now Russia. Max Avdeev for NPR hide caption

itoggle caption Max Avdeev for NPR

Russia established the Crimean port of Sevastopol in the 18th century. After the Soviet breakup in 1991, Russia and Ukraine shared the naval base. But Russia has now taken the entire base, including Ukrainian ships. Max Avdeev for NPR hide caption

itoggle caption Max Avdeev for NPR

Swedish corvette HMS Stockholm patrols Jungfrufjarden in the Stockholm archipelago, Sweden, on Monday. Swedish authorities say they've detected "foreign underwater activity" thought to be a possible Russian submarine. Anders Wiklund/EPA/Landov hide caption

itoggle caption Anders Wiklund/EPA/Landov

An engineer oversees the gas distribution system of Hungary's gas pipeline operator FGSZ in Kiskundorozsma, in August. The distributor announced that it would cut off gas supplies to Ukraine. Laszlo Balogh/Reuters/Landov hide caption

itoggle caption Laszlo Balogh/Reuters/Landov

Technically, it's against the law for Russian restaurants to buy top-notch Italiano Parmigiano-Reggiano. But that's nothing a little creative labeling can't get around. Porter Gifford/Corbis hide caption

itoggle caption Porter Gifford/Corbis

Ukrainian lawmakers applaud a televised address by the President of the European Parliament Martin Schulz (on screen) in the Ukrainian parliament on Tuesday in Kiev. The parliament voted to strengthen trade ties with the EU, but not until 2016. Sergey Dolzhenko/EPA/Landov hide caption

itoggle caption Sergey Dolzhenko/EPA/Landov

Pro-Russian militants take a break at a checkpoint close to where shelling continued Sunday between pro-Russian forces and the Ukrainian army in the village of Olenivka, some 30 kms south of Donetsk on the way to Mariupol, eastern Ukraine. Philippe Desmazes/AFP/Getty Images hide caption

itoggle caption Philippe Desmazes/AFP/Getty Images

Estonian President Toomas Hendrik Ilves (left), with intelligence officer Eston Kohver in 2010. Kohver was arrested by Russian police on spying charges, but Estonian officials called it an illegal kidnapping. AP hide caption

itoggle caption AP

A convoy of Russian trucks crosses the Ukrainian border at the Donetsk-Izvarino custom control checkpoint as Ukrainian refugees look on, Saturday. Russia says the trucks are carrying aid; Ukrainian officials say they don't know what's inside. SERGEI VENYAVSKY/AFP/Getty Images hide caption

itoggle caption SERGEI VENYAVSKY/AFP/Getty Images