How do anarchists respond to the "Hitler would have won without the Allied forces" baloney?

Answer 1

A) Godwin's Law, having to resort to testing unfamiliar ideas against the most infamous mass-murdering dictator in history generally means you've run out of better arguments.
 
B) It's ignorant and dishonest not to see the similar authoritarian tendencies (nationalism) within this society albeit not as spectacular perhaps (not yet anyway). If everyday people were to responsibly ask, in good faith, what traditions, what principles, and what philosophical ideas lead to that mess, they might then instead recognize the utility of those that sought to avoid it. However modest it may be, anarchist ideas could very well be influencing society at large in some small measure (and thus perhaps all the more vital!).

C) As dot's first comment alludes, the hideous spectacle that Hitler became would not have been possible under radically different social, historical, material, and economic conditions.  

D) Hitlers forces were eventually weakened by oil/gasoline shortages. It's difficult to imagine how such problems would play out these days given that states now have to contend with peak-oil limitations in both war and within civil society. Hard to say with certainty but we don't know if "Hitler" is even possible in the same way, or on such a grand scale, in the new millennium.

Answer 2

“5 December 1942: In order to explain the principle, said Heiner Müller, why Stalingrad was on the one hand historically necessary and on the other, from the perspective of human beings, not at all, I have to tell a fictitious story.

Captain Slopotka, Viennese by birth, was transferred to Stalingrad as late as December 1942, thanks to the incompetence of the army administration. Those who in October had initialled the transfer memo knew nothing of the encirclement. He landed at Pitomnik airfield in the middle of a snowstorm. Only days before he had been bathing in the mild winter waters of the Mediterranean at Catania.

He had missed out on all the learning processes in the Stalingrad pocket, had not been subject to the physical emaciation which had already begun in September. He now arrived in the pocket with a fresh view of things. A parachute division, had it been dropped on the winter surface, equipped with special winter clothing and large quantities of ammunition, would have been in the same good spirits and have guaranteed the defense of Stalingrad until early March.

Slopotka, said Müller, becoming more animated, was shocked by the virtually doctrinaire belief of his comrades in the encircled area in their own misfortune. As transport officer, he immediately took charge of snow-clearing duties on the relief airstrip at Stalingradski. Following the suggestion of Air Force Field Marshal Milch, five to seven new airfields were to be organized from scratch in the pocket and that within three days. Slopotka’s vigor, which derived solely from the fact that he had arrived there from another current of reality, was transmitted to his small team. He swept them along. He planned to graduate as an engineer the following year and to take a training course to fly transport planes. Slopotka’s clear spirit did not dominate anything more than the narrow radius of the small airstrip which was still in the same condition in which the Russians had abandoned it in the autumn. It was even impossible to rouse from their lethargy the wireless operators at Pitomnik who maintained radiotelephone communication with the forward air base from which aircraft started for the pocket. So no transport planes were directed to the now cleared runway.

On 24 January, the small group organized by Slopotka was overrun. The Red Army was not interested in the mental state of those it left lying to right and left. Slopotka’s corpse was in a group of dead, leant up against a layered heap of snow, distinguishable from the other dead only in that the layer of fat under his skin still appeared intact.

Key word: BASILISK GAZE. The merchants in the Netherlands, says Müller, were not well versed in the exercise of power and stood back when Alba had Count Egmont executed. They didn’t read the signs. The GDR (East Germany) capitulated in just the same way. Yesterday Valentin Falin visited me, Müller continued. Falin was not at Stalingrad himself. But he had probably read every line in the Kremlin’s secret files about it. According to them, the Russian commanders assumed they had surrounded 86,000 men in their surprise attack. In fact it was 300,000. In terms of numbers, there were never more troops in the encircling front than there were Germans in the pocket. What causes an army committed to lightning war to declare itself defenseless within a matter of two months? The battle is decided, says Müller, in the heads of the fighters.

‘Recently at my house a cat was seen watching a bird on a treetop and, after they had locked gazes for some time, the bird let itself fall as if dead between the cat’s paws, either intoxicated by its own imagination or drawn by some attracting power of the cat.’

—Montaigne, ‘Of the Power of the Imagination’ (Michel de Montaigne: The Complete Works, Donald Frame trans., London, 2003).”