In World War II he served with the Office of War Information in New York and with the Psychological Warfare Branch in the Mediterranean.

The Psychological Warfare Branch, used radio and print media to demoralize enemy soldiers and to discourage enemy civilians.

When World War II broke out, Braggiotti, an American citizen despite his Italian birth, enlisted in the US Army and was put in the Psychological Warfare Branch of the Office of War Information.

In 1941 he was assigned to the Allies' Psychological Warfare Branch (PWB)in Italy, with which he served as an intelligence officer throughout the Italian campaign.

From 1942 to 1944 he served as chief of the Psychological Warfare Branch of the Allied Forces Headquarters in North Africa.

Also using these facilities was the Psychological Warfare Branch of the United States Office of War Information (OWI) under the management of CBS radio chief William S. Paley.

It was headed by US Brigadier-General Robert A. McClure who had previously commanded the Psychological Warfare Branch (PWB/AFHQ) of U.S. General Dwight D. Eisenhower's staff for Operation Torch.

According to then-Captain Alan Abner, the idea of the operation originated from his office at the Army's Psychological Warfare Branch, in Washington D.C..

Miller may have been instrumental in creating the Psychological Warfare Branch of the O.S.S.; certainly he worked for the PWB for the duration of the war.

By the time Germany declared war on the United States in 1941 he had joined the newly created Office of Strategic Services as an analyst, but quickly changed to the Psychological Warfare Branch of the Office of War Information.