The Desert Fox: The Story of Rommel

The film begins with a pre-credit sequence depicting Operation Flipper, a British commando raid whose aim is to assassinate Rommel. It fails.
After the credits, the story is introduced by narrator Michael Rennie, who dubs the voice of then Lieutenant-Colonel Desmond Young, who plays himself in the film. Young is captured and meets Rommel briefly as a prisoner of war; he states that Rommel was not only his enemy at the time, but an enemy of civilisation, and makes it his mission after the war to discover what really happened to Rommel during the final years of his life â at the time that Young wrote his book, it was believed that Rommel had died as a result of the wounds he had suffered when an Allied fighter strafed his staff car.
The film flashbacks to the period of 1941-42, as the British prepare to counterattack Egypt, directed by General Bernard Montgomery: The Germans are defeated at El Alamein in 1942. The situation is made worse when Rommel is ordered by Adolf Hitler (Luther Adler) to stand fast and not retreat, even in the face of overwhelming Allied superiority in men and supplies, but the retreat is allowed. Rommel becomes increasingly disillusioned with Hitler after his pleas to evacuate his men are dismissed. An ailing Rommel is sent back to Germany to recuperate while his beloved Afrika Korps is driven back across North Africa and destroyed.
Rommel is approached while in hospital by an old family friend, Dr. Karl StrÃ¶lin (Cedric Hardwicke), with a request that he join a group plotting to overthrow Hitler. Rommel is very hesitant. StrÃ¶lin departs and immediately afterward evades a Gestapo agent assigned to watch him.
Rommel is placed in charge of defending the Atlantic Wall against the anticipated Allied invasion, though he knows the "wall" offers little protection. When the Allies land in France on 6 June 1944, he and his superior, Field Marshal Gerd von Rundstedt (Leo G. Carroll), are handicapped by Hitler's astrological belief that it is a diversion, with the real invasion to come at the Strait of Dover. As a result, they are denied urgently needed reinforcements, allowing the Allies to secure a beachhead. This is the final straw. Rommel joins the conspiracy. However, when he tries to recruit Rundstedt, the latter excuses himself by stating he is too old for such things, but wishes Rommel well, saying that he will succeed him by morning. (We later hear that Rommel was not appointed his successor.)
Plans are set in motion to remove Hitler. Rommel finally insists on meeting Hitler personally in an effort to persuade him to see reason. Hitler does not heed Rommel's gloomy predictions about the war, screaming that wonder weapons in development will turn the tide. Shortly afterward, Rommel is seriously injured when his car is strafed by an Allied aeroplane. Thus, he is recovering in a hospital when, on 20 July 1944, Colonel Claus von Stauffenberg (Eduard Franz) plants a bomb in Hitler's conference room. It goes off, but the FÃ¼hrer survives. Thousands of suspects are tracked down and executed. An official silence surrounds Rommel.
General Wilhelm Burgdorf (Everett Sloane) is sent by Hitler to present Rommel with a stark choice: be charged with treason, for which the penalty will be excruciating death by garroting, or commit painless suicide. It would be announced that he had died of his previous injuries, he would receive a hero's funeral, his fame preserved and Hitler's regime would avoid scandal. Rommel initially chooses to defend himself in the People's Court, but when Burgdorf hints that Rommels' family would suffer from his decision, he decided to commit suicide to save them. He has the option of receiving a painless drug Burgdorf has brought, and he must do so before evening. He takes leave of his wife Lucie (Jessica Tandy), his aide-de-camp (Richard Boone) and his son Manfred (who suspects nothing wrong), and departs with Burgdorf. As the car is driven away, the film ends with (voice of Michael Rennie) Desmond Young's speculation about Rommel's last thoughts, with brief visual flash-backs of his earlier victories in the Western Desert Campaign from Tobruk through El Alamein, and a final action close-up of Rommel standing in the gun turret of his tank as head of his panzer forces in Africa, with a voice-over tribute uttered in a post-war speech before Parliament by "Nazi Germany's sternest enemy" Winston Churchill, praising the famed Desert Fox.

Question: What is Rommel defending the Atlantic Wall against ?
Answer: Allied Invasion.