I’ve looked this question up and found a couple different answers, one I remember being that the Germans thought Americans were good fighters, and a few others said different things. So just what did the Germans soldiers think of American troops?
Most of what follows is A) based on interviews with German POWs captured in Italy and B) from a U.S. Army newsletter, so there's a certain degree of filtration and sanitization between the true opinions of the soldier and what's on the printed page. With that said, it's even-handed enough to be generally trustworthy.
At least initially, Germans regarded British and American soldiers (especially Americans) as somewhat amateurish, although their opinion of American, British, and Empire troops grew as the war progressed.
German certainly saw shortcomings in the ways the Allied used infantry.
One German veteran of Monte Cassino criticized the Allies’ poor use of camouflage, saying: "they [Allied infantry] are very negligent about seeking concealment, and therefore can be seen most of the time.” He also pointed out flaws in Allied uniforms, noting that: "the net cover on the helmets of Allied soldiers permits us to see the outline of the helmet distinctly, and at a considerable distance, in the daytime.” The soldier felt German camouflage discipline, with some notable exceptions, was usually better.
The same soldier also noted that Allied infantrymen could be overly cautious and tended to “bunch up too much when they move against their objectives.” American soldiers earned special criticism. The POW asserted that American soldiers shot wildly at suspected German positions, avoided close combat, and tended to avoid aggressive action. Furthermore, he claimed that "Allied" soldiers (it’s unclear if he’s referring to British, Americans, or both) moved in predictable patterns that made them vulnerable to sniper fire.
He accused Allied officers of similar weaknesses, claiming that "many Allied commanders lack aggressiveness. They do not realize when an objective can be taken; consequently, attacking troops often turn back just before they reach their objective.”
Yet Allied soldiers could also command a great deal of respect. One German soldier captured in a British nighttime raid praised the skill and courage with which the British attack had been executed. It appears that British units, unlike American ones tended to be better at night fighting and did a great deal more of it. Another German soldier noted that they were “using the night for much of their activity, and have achieved a great deal of success,” and that Allied (probably British) machine gunners “use their machine-gun fire very effectively at night” to pin down German troops.
Some Allied units earned fearsome reputations. German infantryman Werner Mork recounted that Ghurkas “were feared for their daggers [khukri knives] that they would use in hand to hand combat. It always led to death.” Contradictory (but nonetheless chilling) rumors among German soldiers that Ghurkas “never took prisoners” or that they cut the ears off of their prisoners only added to the Ghurka legend. Similar stories emerged about the Moroccan Goumiers who fought for the Free French in Italy.
German soldiers saw poor infantry-armor coordination as another American weakness. Attacks that should have succeeded failed because the two arms cooperated badly. The Panzergrenadier captured at Cassino told his interrogators that a “great distance between Allied armored units and infantry was apparent almost every time. There was one instance when Allied tanks smashed across our foxholes, to be followed an hour later by infantrymen, who were driven back by hail of machine-gun fire. We Germans rely on you to make these mistakes.” In other cases, American troops bunched up too closely with the armor, limiting their ability to effectively support the tanks. A German battalion commander observed that American tanks would immediately retreat if one of their number was hit by anti-tank fire, rather than pressing home the attack.
Although as time progressed, these coordination problems appeared to have been resolved somewhat. By 1945, at least one German observer noted that many American infantry attacks had some form of close support by tanks (or tank destroyers).
It's also worth discussing German reactions towards Allied firepower. German soldiers were consistently impressed with American and British artillery and airpower.
German soldiers noticed that, “as a rule, an attack is preceded by a strong artillery preparation in which the Americans employ all calibers, including their heaviest.” In a letter home, a German veteran of the Sicily campaign wrote that that these barrages could be utterly terrifying. He recalled that even his sergeant, a veteran of the Eastern front, “swore he had never experienced anything like it, even in Russia.” This comment is especially telling, given the Russian penchant for preceding their attacks with massed artillery and rocket fire. Even when uninjured, German soldiers found that Allied barrages badly frayed their nerves.
The intensity of Allied artillery fire lead to some telling German nicknames like the Wagnerian Feuerzaube ("fire magic") or the more industrial automatische artillerie ("automatic artillery"). In some cases, artillery fire alone was enough to force German soldiers to retreat from their positions.
Germans also observed that Allied artillery badly interfered with German supply efforts. When Allied observers could see German supply lines, they could call in devastatingly effective artillery fire that forced the Germans to stealthily bring up small quantities of supplies at night. "Because of Allied artillery fire, our line communications have been cut most of the time," recalled one German prisoner, a panzergrenadier who had spent 16 weeks at Monte Cassino in 1944.
Allied command of the air made Allied artillery even more dangerous. Germans observed that Allied spotter planes were a common (and unwelcome) presence overhead. Allied air superiority meant Allied planes could roam the skies at will. One German veteran said he only saw 2 German planes during the entire Sicily campaign!
This was particularly true during the Normandy campaign. German troops attempting to counter the Allied invasion found it virtually impossible to move during daylight without coming under air attack. Numerous images from the campaign show German soldiers anxious watching the skies, ready to bail out the moment Allied fighter-bombers appeared overhead.
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