What were Stalin's goals in Eastern Europe?

In my opinion, Stalin's main goal in Eastern Europe was to
create a buffer zone that would protect the Soviet Union from the
West.

I suppose some people would say that Stalin wanted
most to spread communism, since that is what communists are supposed to do.  But I think
that Stalin was really more interested in creating space between the enemies in the west
and Russia.

Russia had been endangered by invasions from
the west in 1812 and in 1941.  Both times, the size of Russia saved them.  Stalin wanted
to have even more space so that it would be that much harder for enemies to invade from
the west.