In late 1943, the Italian campaign had reached a turning point; after the decisions made during the Tehran Conference, the supreme military and political leaders of the Allied powers finally decided to give top priority to the opening of the Western Front in German-occupied Europe and thus reduce the importance of operations in the Italian peninsula. General Dwight D. Eisenhower, the Supreme Allied Commander, left the Mediterranean Theater of Operations in December 1943 and returned to the United Kingdom to plan for Operation Overlord, the invasion of Normandy. Shortly afterwards, General Sir Bernard L. Montgomery, commander of the British Eighth Army, was given command of the 21st Army Group and command of the Eighth Army passed to Lieutenant General Sir Oliver W. H. Leese and he, Montgomery, also returned to the United Kingdom; seven veteran British and American divisions were withdrawn from the Mediterranean, waiting to be transferred to take part in the Normandy landings, scheduled for June 1944. Winston Churchill, the British Prime Minister, continued to assign great importance to the Italian campaign on the other hand and despite having shared in general plans for a second front, he considered it essential, to achieve a great victory in Italy. He hoped to destroy the German armies there and build on the success in the direction of Southeast Europe to anticipate the arrival of the Soviet Red Army. Churchill also ordered the 15th Army Group, under General Sir Harold R. L. G. Alexander, to, despite the weakening of their strength, keep pressure on the enemy and attain important strategic objectives and propaganda blows; this included Lieutenant General Mark W. Clark, commanding the American Fifth Army, who was absolutely determined to achieve victory by securing the Italian capital of Rome first. The Allied advance through Italy bogged down around Monte Cassino, which was a crucial point in the Axis defensive position known as the Winter Line. As a result, Allied commanders planned to outflank the Germans with Operation Shingle, an amphibious landing at Anzio. To assist in the landing, Allied forces to the south were to launch attacks in the days leading up to Operation Shingle by seizing German positions across the Garigliano and Rapido rivers; it was hoped that German forces would be drawn away from Anzio to counter these attacks.
Battle
On the night of 20 January 1944, the U.S. 36th Infantry Division, under command of Major General Geoffrey Keyes' II Corps, fired an artillery barrage on German positions across the Gari river, resulting in negligible damage. After the barrage, the 141st and 143rd Infantry Regiments were ordered to cross the river, which began at 19:00. Two rifle companies of the 143rd successfully crossed the river, but German return fire resulted in the loss of too many men and landing boats, and their foothold was abandoned. The 141st fared even worse, being forced to withdraw with heavy casualties after landing directly on a minefield. The next day, both regiments were ordered to perform another attack, beginning at 16:00. Although this assault met with more success, the American foothold was still unsustainable, as withering fire from the 15th Panzergrenadier Division prevented the construction of pontoon and Bailey bridges by engineers. Without the bridges, armor could not assist in the attack, and the infantry were left to fight on their own, resulting in devastating casualties for the two regiments; after more than twenty hours of fruitless combat, both were ordered to withdraw. The 143rd was able to withdraw relatively intact, but much of the 141st was not so lucky as, being stranded, their boats and bridges were destroyed by enemy fire. The German defenders mounted a counterattack against the trapped Americans, capturing many hundreds. Major General Walker, decided against committing the division's last regiment, the 142nd Infantry, and the battle concluded at 21:40 on January 22.
Aftermath
No significant gains had been made in either assault, and the original objective of luring away German forces was entirely unsuccessful. Significant controversy followed the American defeat, with Clark criticizing Walker's execution of the battle plan. Walker responded that the entire battle had been foolhardy and unnecessary, and that Clark's plan, which he had protested against, was all but guaranteed to fail. The battle of the Rapido River was one of the largest defeats suffered by the U.S. Army during World War II and was the subject of an investigation in 1946 by the Congress to establish responsibility for the disaster.
