'Iron Cross' was a US unrealised special forces operation by the Office of Strategic Services conceived initially as a way to infiltrate sabotage teams into the 'Alpine redoubt' which the Allies though the Germans were creating a a final fall-back position in the Alps, and then to seize Adolf Hitler (late 1944/April 1945).

It was in the last part of 1944 that the Allies came to believe that the Germans were planning their 'Alpine redoubt', and 'Iron Cross' was conceived as a means of breaking into this fortress through the use of specially created units of anti-Nazi Germans and German prisoners of war who had come to hate the Nazi concept. These men were to be trained in parachuting and sabotage skills before being dropped, in company strength and wearing German uniforms, into the valley of the Inn river between Kufstein and Innsbruck. Here they were to undertake the sabotage of key installations; create and lead anti-Nazi guerrilla forces; encourage German soldiers to desert; and, if possible, capture high-ranking German military and political leaders.

The operation was conceived on the basis of using prisoners taken or freed during the liberation of France, and including German civilians liberated from the Gestapo, German deserters who had joined the French resistance movement, and volunteers from prisoner of war camps. By the end of 1944, the operation had gathered 175 men to be trained at a special camp in St Germain in sabotage, the laying of ambushes, and parachuting. During this physical training, psychologically testing was used to weed out those who were emotionally unsuitable or morally deficient, and by the end of the training programme exactly 100 men were left.

In the middle of April 1945, the head of the OSS, Major General William J. Donovan, decided on a change of use for the 'Iron Cross' party, which was now to seize Adolf Hitler. In pursuit of this revised tasking, the men of the party were additionally trained in the killing of guards, the storming of buildings, and the extraction of anyone they managed to seize. At this stage none of the men of the 'Iron Cross' party was informed of whom the operation was to seize and extract.

Late in April 1945, the advance guard of 'Iron Cross' was assembled in Dijon, and comprised one US Army officer (Captain Aaron Bank), a radio operator and two soldiers. This advance guard was to be parachuted into the Alps and, wearing German uniform or civilian cloths as expedient, explore and ascertain Hitler’s whereabouts, such as his Berchtesgaden country house in the Obersalzberg area or somewhere deeper in the Alps. Once Bank’s team had established Hitler’s precise location, it would radio the information to its headquarters and the rest of the 'Iron Cross' party would be delivered by parachute.

On 3 April a US agent had been able to interrogate a drunken German officer who two weeks earlier had been in the Reichskanzlei (Reich chancellery), and was able to report that Hitler was currently in this Berlin headquarters, and at 22.000 each night summoned a conference of senior officers. Hitler’s alternative headquarters were at Ohrdruf in Thuringia, and not, as imagined by the Allies, in the Obersalzberg. The Ohrdruf facility was an underground headquarters created for Hitler as the SS’s 'Besonderes Projekt III', but rather than relocate to his headquarters as planned, since the beginning of March 1945, Hitler decided to remain in Berlin.

The launch of 'Iron Cross' from Dijon was delayed for one day six times as a result of adverse weather, and then cancelled as Berlin was clearly an impossible target. The German volunteers of the 'Iron Cross' party were paid but returned to prisoner of war status, but received preference in the process of repatriation after the end of the war.