A senior Russian air force general announced on April 9 that the Kremlin would be supplying Belarus with the new S-400 Triumf -- NATO designation SA-21 Growler -- anti-aircraft and anti-missile interceptor system as part of the joint agreement concluded in February for joint air defense between the two countries.
The agreement was to protect the airspace of what Russia calls the Russia-Belarus Union State and to set up an integrated regional air-defense network.
The new joint Russian-Belarusian air-defense force will have five air force units, 10 anti-aircraft units, five technical service and support units and one electronic warfare unit, and it will have a single Russian or Belarusian air force or air-defense force senior commander, the RIA Novosti news agency reported April 9.
Ever since the disintegration of the Soviet Union at the end of 1991, Moscow's most loyal ally among the 15 former Soviet republics has been impoverished Belarus under the harsh dictatorship of President Alexander Lukashenko.
Belarus has long been the anomaly among the Slavic former Soviet republics in Europe. Ukraine and the three Baltic states of Lithuania, Estonia and Latvia all eagerly embraced the wider world of democracy, freedom of speech, an independent press, free elections, the rule of law and free market economics. But under Lukashenko's iron hand, the people of Belarus, the former Soviet republic of Byelorussia, fell back into a repressive tyranny they had arguably not known since the time of Soviet dictator Josef Stalin.
Nevertheless, under both democratically-inclined President Boris Yeltsin and his much more authoritarian successor Vladimir Putin, the rulers of Russia backed Lukashenko through thick and thin.
Belarus is the most impoverished of all the former Soviet republics in Europe, but it is also, from the Kremlin's point of view, by far the most important in straightforward military and strategic terms.
The road of invasion into the heartland of Russia from the West has always been through Belarus. Most recently, it was seized as the staging ground for the Nazi assault on Moscow in December 1941, and it was then held by the Wehrmacht's Army Group Center for the next three years. More than two million Red Army soldiers died unsuccessfully trying to retake it before it was finally liberated in the huge Operation Bagration of June and July 1944.
Therefore, to this day, maintaining Russia's anti-aircraft and anti-missile air defenses in Belarus to the west of Moscow remains the main focus of Russian defensive strategic thinking.
Just as North Korea serves China by providing an impermeable barrier to the spread of dangerous destabilizing concepts of democracy and political freedom from neighboring South Korea and Japan, Belarus increasingly plays the same role as the Kremlin's shield against influences from the NATO and EU member states of Poland, Lithuania, Slovakia, Latvia and Estonia to the west.
But Belarus' importance to Russia is not just defensive. It also marks the boundary line between the U.S.-led Protestant and Catholic Christian worlds of Northern and Central Europe with the old traditionally Russian-led Slavic peoples of Orthodox Christian Eastern Europe.
Part 2: What makes the S-400 so formidable?