 In approving the plan, Supreme Allied Commander General Dwight D. Eisenhower asserted that the objective was not only to clear the Saar-Palatinate but to establish bridgeheads with forces of the Sixth Army Group over the Rhine between Mainz and Mannheim.The U.S. Third Army of the 12th Army Group was to be limited to diversionary attacks across the Moselle to protect the Sixth Army Group's left flank.Opposing commanders were U.S. General Jacob L. Devers, commanding U.S. Sixth Army Group and German SS General Paul Hausser, commanding German Army Group G.

Significantly assisted by operations of the Third Army that overran German lines of communication, Operation Undertone cleared Wehrmacht defenses and pushed to the Rhine in the area of Karlsruhe within 10 days.