Operation North Wind was the last major German offensive of World War II on the Western Front. On 31 December 1944, German Army Group G commanded by Generaloberst Johannes Blaskowitz and Army Group Upper Rhine commanded by Reichsführer-SS Heinrich Himmler launched a major offensive against the U.S. 7th Army. The 7th Army commanded by U.S. General Dwight D. Eisenhower had sent troops, equipment, and supplies north to reinforce the American armies in the Ardennes - Battle of the Bulge. The initial attack was conducted by three Corps of the German 1st Army of Army Group G and the XXXIX Panzer Corps. By 15 January, at least seventeen German divisions (including units in the Colmar Pocket) were engaged from Army Group G and Army Group Upper Rhine, including the 6th SS Mountain, 17th SS Panzergrenadier, 21st Panzer, and 25th Panzergrenadier Divisions. Another attack, smaller, was made against the French positions south of Strasbourg but it was finally stopped. The U.S. VI Corps was fighting on three sides by 15 January. With casualties mounting, and running severely short on reinforcements, tanks, ammunition, and supplies, Eisenhower; fearing the outright destruction of the U.S. 7th Army, rushed already battered divisions hurriedly relieved from the Ardennes, to reinforce the 7th Army. Their arrival was delayed, and the Americans were forced to withdraw to defensive positions on the south bank of the Moder River on 21 January. The German offensive finally drew to a close on 25 January, the same day that the reinforcements began to arrive from the Ardennes. Strasbourg was saved but the Colmar Pocket was a danger which had to be eliminated. Operation Nordwind, although costly for both sides, was ultimately unsuccessful in its goals. The failure of the offensive allowed the U.S. 7th Army to contain the German push towards Strasbourg and the offensive's gains were erased by the later Operation Undertone.