Instead, the Germans fought their way across the Meuse against second-line
French troops whose tactics and commanders, rather than their courage, failed
them at crucial points. 73 Shrugging off a series of desperate counter-attacks, the
panzers swung west, into the Allied rear. On 17 May, the three divisions in
Belgium were redeployed south. That put what amounted to Germany’s entire
mobile force, nine panzer and four motorized divisions and several smaller
formations, plus elements of the still-embryonic Waffen SS, under Rundstedt’s
command for a killing stroke. French commander Maurice Gamelin was asked
where were his strategic reserves. He replied laconically ‘aucune’ (‘there are
none’). British and French troops already facing strong German forces to their
front did the best they could to cut off the German spearheads. It was not enough.
For tank generals like Guderian and Erwin Rommel, speed was the new
mantra; rapidity of movement and thought was the key to modern battle; the
panzer force was capable of commanding itself. At 2 a.m. on 21 May, the first
German troops reached the coast west of Abbeville. The British Expeditionary
Force, most of a French army group, and the entire Belgian army were cut off and
hoping for a miracle. Seen on a map, however, the panzer spearheads looked like
fingers thrust out from a hand—and correspondingly vulnerable to being seized
and broken one by one. Rundstedt advocated a brief halt to allow the infantry to
catch up and secure the corridors opened by the tanks. Hitler too sought
breathing space to evaluate a situation that had outrun even his imagination.
On 24 May, the panzers were shut down. Dunkirk was left to the Luftwaffe. 74
Did Hitler hold back the armour as a good-will gesture to a Britain he hoped to
conciliate? Did cautious senior generals see an unnecessary risk in sending tank
armour across broken ground against desperate men in prepared defences? There is
no doubt that the tankers were far more comfortable when they turned against France
on 5 June. Within days, a new government, headed by Great War hero Marshal
Phillippe Petain, was suing for peace while it still had some negotiating room.
What made Case Yellow an exercise in operational art was its geographic scope,
its focus on the objective of destroying the enemy forces physically and morally,
and its maintenance of momentum while sustaining tactical flexibility. What took
it off the board in an operational context was the dithering before Dunkirk: a
Fu ̈hrer and a high command equally intimidated by unprecedented success. The
German army would conduct only one more operational-level campaign: the
overrunning of Greece and Yugoslavia in 1941. Finishing off what remained of
the French was a mopping-up exercise. Rommel’s triumphs in North Africa,
although they represented masterpieces of the operational art, lacked the re-
sources to be translated into strategic achievements, even though his own sense
of what they might achieve is often underrated. 75 It was, however, Operation
Barbarossa that definitively marked the end of operational art as a factor in
German war making.
Five interlocking factors were responsible. No less than the cavalry of 1914, the
panzers of 1941 were unsuited for their operational mission. This had little to do
with the often-criticized doubling of the panzer divisions’ number while halving
their tank strength. It reflected an armaments industry with limited production
Prussian–German Operational Art, 1740–1943 55