June 20, 2011:
In a move certain to agitate Russian nationalists, Poland has signed an agreement allowing the U.S. Air Force to base warplanes and transports in Poland. Thus, within two years, the U.S. plans to have F-16s and C-130s stationed in Poland. This is seen by Poland as a further protection from Russian pressure and threats. For over two centuries, Russia has regularly threatened, and often seized parts of, Poland. Russia is not happy with anything that might prevent more such moves in the future. Since the United States is a nuclear power, Russia will be constrained from moving on Poland as long as American troops are stationed there. But the Russians will definitely not like it, and this pleases the Poles a great deal.
This is a complicated part of the world. For example, Poland borders a small part of Russia; Kaliningrad. This is the former German city of Konigsberg (founded by German invaders in the 13th century). Konigsberg was taken by Russia in 1945, and ceded to them (and renamed Kaliningrad) as part of the many political changes resulting from the end of World War II. All the Germans were expelled from Konigsberg, and the area was resettled by Russians. This was part of the destruction of Prussia, the easternmost German province, and long the jumping off point for German invasions to the east. When the Soviet Union was dissolved in 1991, Russia hung on to Kaliningrad, even though it was now surrounded by non-Russian territory.
To many Russians, the Germans have been replaced (or reinforced) by the Americans, and are seen as the source of yet another invasion from the west. This invaders have been coming for over a thousand years, and those memories die hard in Russia.