On Monday, February 13th, 2012, at 11:09:38h +0000, David Looser wrote:

It seems that the invasion of the Soviet Union was Hitler's ultimate
aim all along, the other invasions: Czechoslovakia, Poland, France etc.
were just "warm-ups" for the main event.

My understanding was that the most important strategic reason for the
eastward invasion was to take hold of the oil refineries and wells
in Grozny and Baku which were needed to keep the German
industrial-military complex going and of course to deny these
supplies to the USSR which was dependent upon them.