The Russian Black Sea Fleet sank a mothballed cruiser in the inlet to Crimea's Donuzlav Lake on March 5, effectively blocking access to the sea from Ukraine's primary naval installation on the peninsula. Seven of the Ukrainian navy's estimated 25 ships are reportedly trapped in the port of Novoozerne. This action serves several purposes for the Russian forces operating in Crimea. It provides a way, albeit and impermanent one, for Russia to free up military assets for other uses. The Kremlin's operational planners still want to deny Ukraine the ability to concentrate force as the crisis continues, so isolating Donuzlav Lake is thus a prudent move. Moreover, sinking the ship may also give Russia a possible new bargaining option. Much of the present day Ukrainian navy was appropriated from the former Soviet navy after the break up of the Soviet Union in 1991. In time, Russia might choose to retake part of its "lost fleet," depending on how negotiations play

A natural gas pipeline in Boyarka, Ukraine. (SERGEI SUPINSKY/AFP/Getty Images) Summary To try to mitigate Russian influence in Europe, members of the U.S. Congress have increased pressure on the White House to fast track approvals of U.S. natural gas exports. Recently, Moscow has canceled discounts on natural gas exports to Ukraine to pressure Kiev over the situation in Crimea . The move highlighted Russia's strength as an energy exporter , which would not be threatened by increased U.S. natural gas exports. While Washington certainly has an interest in countering Russian influence, it is limited in its ability to strategically deploy its own energy exports for geopolitical purposes. Instead, the United States will support projects that diversify energy supplies to countries in Russia's periphery, including Ukraine, to help ease their reliance on Russian energy. Analysis Thanks to the ongoing shale gas revolution , the United States will emerge as one of the world's larges

The prime ministers of the Visegrad Group countries (L-R, the Czech Republic's Bohuslav Sobotka, Poland's Donald Tusk, Hungary's Viktor Orban and Slovakia's Robert Fico) at a news conference in Budapest on Jan. 29. (ATTILA KISBENEDEK/AFP/Getty Images) Summary Since the beginning of the decade, concerns about political fragmentation in the European Union, the emergence of a more assertive Russia and the commitment of NATO and the United States in Central Europe have given new life to the Visegrad Group. Foreign ministers of the group -- a platform of political and military cooperation among Poland, the Czech Republic, Slovakia and Hungary -- met with their counterparts from the Nordic and Baltic states in Narva, Estonia, on March 6-7 to discuss ongoing issues, including the situation in Ukraine. Foreign ministers and deputy foreign ministers from Poland, the Czech Republic, Slovakia, Hungary, Denmark, Finland, Iceland, Norway, Sweden, Latvia, Lithuania and Estonia conde