Interview with WWII reconaissance pilot

[ATAG_Dutch]

Originally Posted by WTE_Galway

More significantly, at the time of first invading Poland, Heinz Guderian and co were all (surprise surprise) over in Poland. Hitler took a huge risk against the advice of his own military and left the western border with France undefended during the Polish campaign. This was a massive gamble hoping that the French and British would hold back on attacking until they felt more prepared. The gamble paid off.

In other words an attack by the French/British at the time Germany was tied up in Poland may well have succeeded.

Agree with most of your post, although Britain and France would not have gone against the wishes of Belgium and Holland in order to go around the 'Siegfried line', which although in the process of being built from 37-39 and into 1940, even with the commitment of forces elsewhere would still have been left reasonably manned.
This is why I said I 'can't envisage what form this would take' in the previous post, as the only other option available would be to plan a seaborne invasion of either northern Germany or Poland itself for which neither Britain nor France were equipped. The fleet would have been harried every step of the way, outside of the range of effective fighter cover
Attempting to go through the Siegfried Line, could easily have resulted in 14-18 conditions for a short time. Then once the main German Forces returned from Poland......