Why did the nazis go to with the u. s. and why did they half of france the whole thing

Since July 1940, upon being invaded and defeated by Nazi German forces, the autonomous French state had been split into two regions. One was occupied by German troops, and the other was unoccupied, governed by a more or less puppet regime centered in Vichy, a spa region about 200 miles southeast of Paris, and led by Gen. Philippe Petain, a World War I hero. Publicly, Petain declared that Germany and France had a common goal, “the defeat of England.” Privately, the French general hoped that by playing mediator between the Axis power and his fellow countrymen, he could keep German troops out of Vichy France while surreptitiously aiding the antifascist Resistance movement.

Petain’s compromises became irrelevant within two years. When Allied forces arrived in North Africa to team up with the Free French Forces to beat back the Axis occupiers, and French naval crews, emboldened by the Allied initiative, scuttled the French fleet off Toulon, in southeastern France, to keep it from being used by those same Axis powers, Hitler retaliated. In violation of the 1940 armistice agreement, German troops moved into southeastern-Vichy, France. From that point forward, Petain became virtually useless, and France merely a future gateway for the Allied counteroffensive in Western Europe, namely, D-Day.