Why the Nazis did not use Chemical Warfare

By Stephen Bryen

When Shawn Spicer made his gaff on the Nazis and using poison gas, seemingly forgetting the use of Zyklon B on millions of concentration camp prisoners, everyone was willing to agree that the German Army did not use chemical weapons in battle in World War II, except one lone possibility of the use of poison gas in Russia.  As not using chemical weapons was a huge departure from World War I, where the German military used tons of the stuff (as did the allies), why didn’t they use it once again, especially when they were clearly losing the war?

Shawn Spicer

The use of chemical weapons in World War I, weapons that included mustard gas, phosgene and chlorine –all in violation of the Hague convention of 1899 which “especially prohibited the use of poison or poisoned arms” –did not lead to any punishments after World War I.  In fact, one of the most famous promoters of chemical arms, who served on the battlefront and who also was the inventor of Zyklon B, was Germany’s Max Haber.  He was awarded the Nobel Prize in Chemistry in 1918 and was honored by most of the leading scientific organizations in Europe and the United States after the war.  He died of a heart attack on his way to Palestine in January, 1934 to take up a post at the Sieff Institute, now the Weizmann Institute in Rehovot, Israel. Nor did it matter, it seems that Haber was Jewish (although a late Lutheran convert) and a number of his near family members later died in the Holocaust, killed by Zyklon B.

Max Haber (in uniform) at his wedding to his second wife with his son. His first wife, Clara Immerwahr committed suicide in 1915 opposing Max’s chemical weapons work.

Thus it was not the prohibition on the use of chemical weapons, or the thousands of deaths they caused, or the fear of punishment after the war that can explain why such weapons were not used in World War II.

It is sometimes argued that it was Hitler himself opposed the use of chemical weapons because he was a victim of a gas attack in the Ypres salient which blinded him.  But modern research suggests that Hitler made up that he was blinded by a chemical attack to hide the fact he suffered a severe mental breakdown, a victim of what we would call PTSD.   

But Germany was preparing for chemical warfare during the interwar years and during World War II itself.  However, the evidence seems to suggest that Germany’s military leaders were far from convinced using chemical weapons would be effective, and they certainly feared retaliation by the Allies.

World War I was a war that focused on fixed lines, limited mobility and trench warfare. Chemical weapons were introduced specifically to break the stalemate on the front where trench lines characterized the position of opposing armies.  Attempts to break out, to go over the top (as leaving the trenches and attacking was called) mostly failed and took a huge toll in casualties.  While the allies suffered more than the Germans, who used artillery and machine guns to huge effect, the German army was looking for a way to chase allied troops out of the trenches and force them into retreat.   Thus the purpose of firing chemical canisters and artillery rounds at the enemy: the chemical agents in the form of a low-hanging gas were expected to seep into the trenches causing the enemy to fall back.  While the enemy had gas masks (even work animals including donkeys and horses had them), they did not have protective gear against blister agents such as mustard gas.

But the use of thousands of tons of chemical weapons did not have the desired military impact supposed, and it did not force any retreat by the allies.  And, as the allies fired back with their own blister agents and poison gases, the Germans realized that their chemical weapons campaign was backfiring on them.  To this one can add that if the wind shifted, chemicals would blow back on troops, causing as much harm to them as to the enemy.  Therefore from a military point of view, a lot of soldiers (and many civilians and animals) were killed but it did not change the war’s result.

World War II was quite a different affair than the First World War.  Air power was now an important factor in warfare, as were mobile forces including heavy armor.  The Germans focused on blitzkrieg and while they built plenty of fortifications to block any allied counterattack, German forces enjoyed success when they were attacking which enabled them to gain massive amounts of territory.  It was only when German forces were forced into lengthy and static battles that they took the heaviest losses and failed to overwhelm.  The earlier justification for using chemical warfare agents did not fit the model of highly mobile forces.

The Germans searched for some kind of decisive chemical agent that might be useful as a weapon capable of terrorizing allied forces.  They thought they found it in nerve gas: both SARIN and Tabun A and B.  These they manufactured in large quantities secretly in underground bunkers.  To hide their program, they set up fake companies and programs, although production was always in the hands of I.G. Farben, the same company producing Zyklon-B.  The Germans could, and did test their new chemicals on prisoners of war and on inmates of German concentration camps, so they knew they worked and were able to develop doctrine on how to use them.

The brutal and bloody allied Italian campaign started in July, 1943 in Sicily and then to the Italian “boot” under Operation Husky.  As the allies moved northward there was increasingly solid intelligence information that the Italians were preparing to use chemical weapons, probably mustard gas. This led Franklin Roosevelt  to dispatch allied chemical weapons, in the form of mustard gas shells, to the battlefront.  A secret shipment, perhaps not the only one but the only one that is documented, was loaded onto a ship called the John Harvey.   The John Harvey was a brand new liberty ship launched in January, 1943 at Wilmington, North Carolina.  It was carrying 2,000 M47A1 mustard gas bombs, each of which held 60–70 lb of sulfur mustard and had left Algiers for Bari, Italy along with many other supply ships and troops then arriving at Bari.  In retrospect it is clear that the Germans had good intelligence that the allies were moving mustard gas to the battlefront, which they probably got from their agents in Algiers.  Germany’s Luftwaffe launched a raid before the mustard gas shells could be offloaded –the raid was a huge success and the John Henry was sunk after exploding.  There were 628 mustard gas military casualties of which some 69 died over a two week period.  Even more, civilians in Bari suffered from mustard gas though the number of casualties is not known.  Forced by circumstances, the U.S. had to admit it had shipped in mustard gas bombs.  With the loss of the John Harvey, the threat to use chemical arms ended.

One of the ships on fire at Bari harbor after the Luftwaffe raid

The Germans still could have tried to use nerve gas, but additional threats  came from the allies, especially from Winston Churchill who threatened to hit German cities with chemical weapons and anthrax.  Germany’s military leaders were well aware their colleagues in Japan were using chemical and biological agents against China; so they knew what could happen to civilians when attacked by combinations of these agents.  German civil defense did not provide gas masks or protective gear to average citizens, leaving Germany wide open to an allied attack.  Germany’s leadership was rightly worried about panic, the loss of political control, even the failure of the Nazi regime.


On top of their worry about Churchill’s strong threats, which were taken very seriously was the fact that the new nerve gas weapons were tricky to use and extremely dangerous.  Mixing together the chemicals was risky, leaks were to be expected, and environmental and other factors raised many doubts the weapons could be used.  Thus faced with allied determination to use chemical weapons if the Germans did, the risk to their cities, and the fact that the newest nerve gas weapons were extremely dangerous, Germany’s military leaders opted out.

One wonders that, instead of sending in cruise missiles the United States told the Syrians we would drop nerve gas on them whether Syria would have better understood there are real consequences to using chemical weapons.  Certainly Franklin Roosevelt and Winston Churchill sent the right message to Hitler, a message that was confirmed when the Luftwaffe struck the John Harvey.