'Pig Iron' was a US operation by the Office of Strategic Services to undermine German morale by the placement of disinformation in German newspapers (1945).

Together with 'Sheet Iron', 'Pig Iron' was the major and indeed maiden foray by the Office of Strategic Services' Morale Operations department into the field of free leaflet dropping, a field which had been dominated by the Psychological Warfare Branch of General Dwight D. Eisenhower’s Allied Force Headquarters the last months of the war.

'Pig Iron' resulted in the delivery of more than 10 million miniature editions of the Das Neue Deutschland black propaganda newspaper into the German homeland as a supplement to the standard monthly distribution of 75,000 full-size copies through the Morale Operations branch’s clandestine channels.

There were obvious difficulties in dropping black propaganda over Germany from Allied warplanes and then having it accepted by the German public. Thus there were only a few of the Morale Operations branch’s 'production' items which were of use for this system of dissemination, and there was also opposition from the Psychological Warfare Branch, which argued that black propaganda and white propaganda should not be dropped together, arguing that their proximity would have a deleterious result on each of them. In the case of Das Neue Deutschland, the Morale Operations branch solved this difficulty by describing the newspaper as a 'captured enemy document', and this specious claim made it feasible to send the paper back to the Germans in large quantities as evidence of what enlightened Germans were thinking and saying within Germany itself.

The newspaper was photographically reduced to a size of 10 by 6.5 in (25.4 by 1.65 cm), one-quarter of its standard size, and the newspaper was initially reproduced at the rate of 1 million per month, although after the Psychological Warfare Branch had abandoned its control over the drops, the printing and distribution rates were quadrupled to 1 million per week.

However, this posed new problems for the Morale Operations branch as while the branch’s production volume had been high, compared to other propaganda-distribution agencies its demands for paper and printing ink had been comparatively low. The new production schedule called for a very considerable quantity of paper and ink each week, and also lengthened the hours of the Morale Operations branch’s print shop employees. Only the Morale Operations branch’s well-honed experience of 'obtaining' supplies saved the day.

Bundles of 1,500 copies of the newspaper had to be packed into a special cylindrical device which could be loaded into the standard propaganda bomb. They were then transported by truck to the Morale Operations branch’s base at Foggia in south-eastern Italy and packed into bombs, which were then turned over to the USAAF to be dropped over central Germany and Austria.

The 'Pig Iron' undertaking received the compliment of a very strong reaction from the German press. In a two-page article, Reichsführer-SS Heinrich Himmler’s own newspaper Das Schwarze Korps denounced Das Neue Deutschland and its 'traitorous' authors, and was also angered about the possibility that Germans might use a card delivered with Das Neue Deutschland to ingratiate themselves with the Allies.

When the German front in Italy collapsed and very large numbers of prisoners were taken, it was found that a significant proportion of them had either read or heard about Das Neue Deutschland, and had clipped the coupon, which they filled in and hid in their caps and shoes.