One of the things that I have noticed about military history is, in general, the closer you get to the modern era a particular battle or event will cover a whole lot more land. Take ancient times – battles were fought in just one place. You could place the exact spot and that major battle would go all day and then it was recorded. Go up to medieval times and it’s about the same. After this though a battle may start to move and go over several days. In Napoleonic times and you’re covering swaths of countryside. WWI is almost a slide back in that you have miles of front but not much moving at all but the battles cover months. Then there is WWII. Miles and miles covered in a day and sometimes the entire battle is fought over a moving battlefield and whole swaths of countries as mechanized units rapidly progress. Operation Cobra, the breakout from Normandy for the Allies, represents a classic in mobile warfare with exploitation of events, rapid encirclement, and represents the major change in tempo in the final years of WWII – moving ever rapidly into quick and mobile warfare.
If you think a bit more about how much warfare was changed by the aspects of mobile warfare, the mental strength of the generals involved (on both sides) is really quite astounding. Mechanized warfare had been around for awhile, but to really master it and all the logistics that it requires to pull it off from a combined arms perspective (ground troops, tanks, supply trains and air support) is really impressive because you have to think in depth and in 3 dimensions. This is where the operation begins – planning for a breakout from Normandy. The generals in charge of planning are all the big names – Bradley, Patton, Eisenhower, along with some other names not mentioned as often who played key tactical roles in the operation. Even British general Montgomery played a role, but this is really a US operation so really one must focus there when understanding the breakout. Certainly the British helped by tying up forces in the North (a huge drive that failed cause the Germans to believe that the primary thrust would be in that sector, not in the American sector) but the exploit and breakout is strictly an American success.
Tactical and technical innovation in reaction to local events were also important to this operation. Part of the issue slowing down the US forces in the Normandy area was the terrain, which was heavy with “Bocage” which is a thick mat of trees and shrubs that serves as its own fence and wall between farmer plots throughout the Normandy area. This terrain suited the defender perfectly such that troops going past could be easily ambushed by forces on the other side of Bocage. So tanks were fitted with special blades and bulldozers to uproot the Bocage at its roots allowing penetration through the walls. The blades were created from anti-amphibious obstacles welded together by the Germans prior to D-Day and were fitted onto Sherman renamed “Rhinos” after some engineers began to think about how to get through the Bocage. So this was a good innovation. An example of bad innovation (or at least it didn’t work as well as intended) was the use of camoflauge uniforms. Giving troops a lot of camouflage uniforms to help them move quickly through Bocage terrain stealthfully turned out to be a very bad idea in that most US troops associated camouflage with Waffen SS units and there were lots of friendly fire incidents with the elite US units given these uniforms. So the US numerical superiority was important to breaking out, but the other key factor and innovation which assisted the breakout was air power and artillery. Air power would be the use of low altitude 100lb carpet bomb attacks prior to the start of the assault plus localized fighter bomber attacks on enemy armor columns. Artillery I’ll come to later.
The plan was to use air power to smash the enemy divisions on the front line and then immediately follow up with an armor offensive, rapidly breaking through the German lines. The attack would commence around St. Lo and then push out and rapidly accelerate to the French west coast – cutting off bridges in the south as well so that the Germans could not reinforce their lines from other parts of France. On July 24 the operation got off to an aborted start when weather prevented the bombing run but due to some bad communications, some bombs were dropped anyway both on friend and foe alike. Enough bombs were dropped such that the Panzer Lehr division, a large tank + infantry division, thought that it had survived a major attack (10 vehicles lost, 350 killed) and moved forward to new dug-in positions expecting to repulse a major attack by US armor. Instead on 25 July the actual full bombing attack commenced and Panzer Lehr took the brunt of it since it had moved directly into the new bombing zone – 1000 troops killed and about half of their armor damaged in the attack. At this point the US began the ground offensive but it didn’t get very far since some of the German units which had moved forward very close to US lines were completely missed by the bombing attack and had to be taken out the old fashioned way. However this did not occur all along the line and units did begin to pour through the gaps. By 28 July the Americans had pushed through so much that several German units were about to be encircled, leading to the first major lopsided victory in American favor when the entire 2nd SS Panzer Division, “Das Reich” was wiped out as they tried to escape and fighter bombers just strafed and bombed the main road out of their pocket repeatedly. This event and others by July 29 led to a complete change in the original plans. Rather than consolidation of gains the decision was made to move to exploitation and race further down the coast to Brittany.
By July 30 the US forces were rapidly moving along such that the French coastal cities of Brest, Lorient, and St. Naizaire were rapidly encircled and the German garrison forces in siege mode by August 7th. From breakout to the encirclement of Brest, the movement by the US 6th Armored division was the most extended operation done by any US division in 1944 to 1945 and over such a quick period of time as well. The fact that they were able to exploit the breakdown in German defenses and hold together a coherent front and operations is testament to the superior organizational skills of the US command. This however was not the end of the operation.
On August 7 the Germans staged a counterattack led by a the remnants of several armored units that were assembled together. The night attack by the German units quickly pushed into and took the town of Mortain with no opposition, but this ultimately did no good because the US forces in the area were not at Mortain, but were entrenched on the hill overlooking the town (now behind German lines) which gave them excellent views of the units in town and the roads leading in and out of town. So while this main thrust moved another 6 miles and encountered the main body of the nearby US forces (not the units on the hill mentioned previously) the other arm of the German counter-attack never launched its attack due to poor inter-force communications. The US response to these events shows how far the Germans had fallen in the recent days. US initial reaction was “…the attacks appeared to be uncoordinated units attempting to escape rather than aggressive action.” but later the US realized that the attack was indeed a larger offensive. However once dawn broke the hills surrounding Mortain now had clear views of the the German forces, and these hills was where localized US divisional artillery had been located and they now began to pour shells down on the visible Germans. And then the US forces on the hills added insult to injury by calling in air strikes they could act as forward observers for. 294 sorties from Rocket armed British Typhoons and 200 sorties from US P-47s occurred in this area which caused the entire German counter-attack to bog down into a defensive operation. Now this operation plus the Canadians launching a major offensive in the North tied down the Germans so completely that Patton was free near Le Mans to begin a pincer movement to seal off the Germans completely. You almost have to feel sorry for the German command here – they were outnumbered, outgunned, and every time they turned around they had another major offensive to deal with.
The final events of the campaign deal with Patton and the Canadians encircling the Germans and the Allied race to the Seine river. The Allied forces did indeed encircle the Germans except for a gap in the line at Falaise (The famous Falaise Gap). While some generals pushed for closing the gap, Bradley was concerned that the Canadian thrust and Patton’s thrust would come to a head too fast and lead to some friendly fire incidents, plus it would be difficult to call in air support without allied losses from allied air strikes. Further he was concerned that his flanks were exposed since these pincers were deep into enemy territory and he had false intelligence that the Germans were withdrawing from Falaise rapidly. No one could believe that the Germans would lock up their forces in one area and allow them to be surrounded, but they had no knowledge that Hitler’s meddling led to the poor German decisions. So slowly the Allied pincers closed within 15 miles of each other and on August 15 the Allied landed forces in Southern France (Operation Anvil-Dragoon). Now with German forces in southern France tied up dealing with this unopposed amphibious landing, the Allies were free really punish the Germans. Finally with some regret Hitler authorized the withdrawal of units in the south of France and the units trapped near Falaise but now it was too late. Constant air strikes, fortified positions and rapidly moving armor columns closed up the pocket and while about 20,000 to 40,000 Germans escaped, by August 21st about 50,000 were captured with another 10,000 dead and all local panzer and German military equipment had been smashed beyond recognition. As described in the book, the Germans were surrendering in droves to stop the incessant artillery fire in the pocket.
So all this was done by August 21st, but on August 18th the Allies were in striking distance of Paris and due to unrest in the city, despite Hitler’s commands to the local garrison to burn the city to the ground, the German garrisons surrendered or left the city by August 25th. I won’t discuss this aspect of the battle so much because the book does it better, but also because this final event really sums up the entire campaign. A breakout plan that went so successfully that it broke several German divisions permanently, liberated a huge portion of France, unexpectedly delivered Paris, and gave the momentum to the Allies for the rest of the war. Quite an operation and truly an amazing event in US military history being an example of good planning and taking advantage of opportunities as they presented themselves. The combined forces of massed artillery, air strikes, and mobile armor columns greatly helped win the battle – but again you have remember it is the coordination of all that firepower that made the campaign go so well. And when you consider that this occurred over such a wide theater and a short period of time (3 July to 25 August) this again is truly impressive.
If you wish to learn more, check out Osprey Campaign Series #88 by Steven J. Zaloga. It’s a good read and has lots of detail and useful information if you wish to learn more beyond what I’ve summarized above.