Speculation indeed.  My guess is that the fact that France did not attack during the Poland campaign means that they would never attack, so Hitler could ignore them.

As to the article, I had already made the chage above which resolves that issue for now.  I would prefer if someone more knowledgable would expand the sentense into a proper paragraph.  But not to just leave it as it was.

I am also a little concerned about the following statement, which reads as if Hitler was forced to act.

Halder argued that, as Germany's strategic position seemed hopeless anyway, even the slightest chance of a decisive victory outweighed the certainty of ultimate defeat implied by inaction.