Britain and France declare war on Germany - Sep 03, 1939 - HISTORY.com
As for Britain’s response, it was initially no more than the dropping of anti-Nazi propaganda leaflets—13 tons of them—over Germany. They would begin bombing German ships on September 4, suffering significant losses. They were also working under orders not to harm German civilians. The German military, of course, had no such restrictions. France would begin an offensive against Germany’s western border two weeks later. Their effort was weakened by a narrow 90-mile window leading to the German front, enclosed by the borders of Luxembourg and Belgium—both neutral countries. The Germans mined the passage, stalling the French offensive.
When The French Army Invaded Germany in 1939 To Support Poland, All Did Not Go As Planned
Germany was not the first country to go on the offensive on the western front of World War Two. That first attack came from France, which launched a brief and ineffective invasion of Germany in September 1939. This
That first attack came from France, which launched a brief and ineffective invasion of Germany in September 1939. This attack, intended to help the far-away Poles, became an embarrassing defeat and a harbinger of what would follow when Germany invaded France.
What followed was Operation Saar, an invasion of the German region of Saarland. Unfortunately for the French, the restrictions that bound them to this plan would also ensure its failure.
The French did not want to violate the neutrality of Belgium by taking armed forces across its territory. As a result, they could only attack Germany along a limited front. This front had been defined 125 years earlier, during the peace process following the Napoleonic wars, when the rest of Europe was concerned with containing French aggression. It gave the Germans the advantage of the defensive high ground.
Still, the French had made a promise to Poland, and they lived up to it. On 7 September they invaded Saarland with a limited force, which was due to be followed by a full-scale invasion a few weeks later. Forty divisions were sent in, with 4,700 artillery and 2,400 tanks.
Facing them were 22 divisions and less than 100 artillery pieces of the German 1st Army.