This is one of the reasons because of his
success with the Blitzkrieg he decided it was
time to go for a bigger target, and have already conquered the eastern part.
The France already had planed an attack from Germany and
created the Maginot line, but the Germans were smart and they
decided to attack from the Belgium frontier.
France signed the armistice on June 22, 1940 and Germany established
their own government named Vichy government
Withdraw of
France
Phoeny war
That France and UK did not attack even
after declaring war