The American army hoped to outflank the Germans in Italy and launch an attack on Rome. They landed an amphibious force at Anzio and Nettuno achieving complete surprise. Unfortunately for the Allies, the field commander failed to capitalize on the advantage. General John P. Lucas preferred to take his time, consolidate, and defend against an expected counterattack. His delay allowed the Germans to strike the beachhead, pin down the Americans, and led to a six month bloodletting rather than a quick victory.
Axis powers successfully halted the Allied advance on Rome. The defensive line became known as the Gustav Line under the command of Field Marshall Albert Kesselring. British Prime Minister Winston Churchill believed an amphibious landing at Anzio would allow the Allies to slip past Kesselring’s defenses and capture Rome. If Kesselring moved to blunt the landing, then the troops at the Gustav Line could break through. If not, then the invading force could flank the Nazis and march on Rome.
General Mark Clark assumed command of the mission. He feared the Allied High Command did not provide enough troops for the assault. Some worried Kesselring would be able to both defend the Gustav Line and Anzio. In this case, the battle could become a meat grinder. However, these concerns were ignored. The planners felt that either the Allies would take Rome or bog the Germans down in two spots on the Italian front.
Clark made his orders plain to Lucas. The Americans had to seize the Anzio beachhead, secure the Alban Hills, and then take Rome. However, Clark did not provide a timetable for Lucas. He evidently expected stiff resistance and Lucas had little faith in the plan. In fact, he believed Anzio would be a repeat of the Gallipoli bloodbath orchestrated by Churchill in World War I. As a result, Lucas was given wide latitude for the advance. This proved disastrous for the American force.
The battle began successfully for the invaders. They landed unopposed on January 22, 1944 with the exception of some Luftwaffe sorties. The Americans landed 36,000 soldiers in short order, with only 100 casualties. The lack of resistance caught the Allies by surprise. Rather than capitalize on German surprise, Lucas decided to consolidate and continued to land supplies on the beach. Churchill compared the invasion force to a “beached whale.”
Lucas had three options and chose the worst. He decided to stay put because he lacked the confidence in the operation. However, he could have raced to Rome, but that likely would have resulted in disaster once the Germans moved. Lucas should have moved inland to a better position in order to protect his men, consolidate, and attack the enemy. His inaction created a shooting gallery for the Germans.
The assault surprised the Germans, but not necessarily Kesselring. The field marshal planned for the attack as a contingency. Kesselring put his defense plan into motion at breakneck speed. He decided to attack the landing site and consolidate his own defenses. The German quickly moved troops to the Alban Hills and requested reinforcements from France and Yugoslavia. Within three days, the Nazis surrounded the invasion force at Anzio.
The 36,000 Allied troops faced 25,000 German and Italian soldiers at the outset. Each side filtered more troops into the battle. By the end, 150,000 American and British soldiers battled 135,000 German and Italians. Lucas launched a breakout attempt on January 30, but the battle eerily replicated World War I’s western front. Men died in droves for limited gains. The breakout failed and the Nazis counterattacked. At one point, the Germans nearly broke the Allied lines at a salient near Campoleone.
The two sides continued the back and forth nature of the combat into February. Churchill attacked Lucas’ competence and finally managed to get him replaced. Lucian Truscott assumed Allied command, but stalemate developed. The frustrated Allies planned for a breakout and Operation Diadem was born. The Allies launched Operation Diadem to breakout on May 23. Artillery announced the offensive to the Germans in another action reminiscent of World War I. The 1st Armored Division lost almost 1000 casualties in the first day, which was the highest single day total for any American unit in the war. The two sides slugged it out and even fought house-to-house as the Allies advanced.
On May 25, Clark ordered his main line to turn 90 degrees to the left while moving the 1st Armored to withdraw and prepare to breakout. Meanwhile, Kesselring continued the chess match by deploying forces to halt the Allied advance on Route 6 to Rome. The battle turned when Allied forces slipped into a gap between German forces. The 36th Division had to climb Monte Artemisio’s slopes to achieve the advantage. The Germans quickly withdrew from their positions while the Americans managed to slip around the Alban Hills and moved on Rome. The German defenses collapsed on June 2. General Clark entered Rome on June 4. However, Operation Diadem failed to destroy the German army in Italy, which led to sustained bloody fighting into 1945.
The Battle of Anzio cost around 40,000 casualties for each side. The Allies lost around 7,000 dead while the Axis powers suffered around 5,000 deaths. The initial assault lacked the requisite number of troops for instantaneous success. Despite this, General Lucas could have done more than sit on the beach and wait for the German onslaught. His lack of initiative led to a six month standoff that need not have happened. Although the Allies captured Rome, the Germans maintained an effective battle force in Italy. As a result, the Battle of Anzio proved a debacle for the Allies despite the victory.