The Phoney War, also called the Twilight War by Winston Churchill, der Sitzkrieg in German ("the sitting war": a play on the word Blitzkrieg), and the Bore War (a play on the Boer War) was a phase in early World War II – in the months following the German invasion of Poland in September 1939 and preceding the Battle of France in May 1940 – that was marked by a lack of major military operations in Continental Europe. The great powers of Europe had declared war on one another, yet neither side had committed to launching a significant attack, and there was relatively little fighting on the ground.
While most of the German army was engaged in Poland, a much smaller German force manned the Siegfried Line, their fortified defensive line along the French border. At the Maginot Line on the other side of the border, British and French troops stood facing them, but there were only some local, minor skirmishes. The British Royal Air Force dropped propaganda leaflets on Germany and the first Canadian troops stepped ashore in Britain, while western Europe was in a strange calm for seven months. Meanwhile, the opposing nations clashed in the Norwegian campaign. In their hurry to re-arm, Britain and France had both begun buying large amounts of weapons from manufacturers in the US at the outbreak of hostilities, supplementing their own productions. The non-belligerent United States contributed to the Western Allies by discounted sales, and, later, lend-lease of military equipment and supplies. It should be noted that in the 1930s, in a much smaller scale, private companies in Britain and the US were also supplying Germany, without government sanction. Engines of a few German fighters were made in Britain, and American raw materials were being sold to Germany. German efforts to interdict the Allies' trans-Atlantic trade at sea ignited the Second Battle of the Atlantic.
Jodl at the Nuremberg Trials said that "..if we did not collapse already in the year 1939 that was due only to the fact that during the Polish campaign, the approximately 110 French and British divisions in the West were held completely inactive against the 23 German divisions."
The Phoney War was also called "Funny War". Winston Churchill called it the "Twilight War". The term has equivalents in many other languages, notably the German Sitzkrieg ("sitting war," a play on Blitzkrieg) or komischer Krieg ("funny war" or "strange war", komisch having two meanings), the French drôle de guerre ("strange war," drôle which can also mean "funny" stands for "strange" when used like this), the Italian guerra fittizia and finta guerra (respectively "fictitious war" and "false war") and the Polish dziwna wojna ("strange war"). In Britain the period was even referred to as the "Bore War", (a pun on "Boer War").
The Saar Offensive was a French operation into the Saarland on the German 1.Armee defence sector in the early stages of World War II. The purpose of the attack was to assist Poland, which was then under attack. However, the assault was stopped and the French forces withdrew.
According to the Franco-Polish military convention, the French Army was to start preparations for the major offensive three days after mobilisation started. The French forces were to effectively gain control over the area between the French border and the German lines and were to probe the German defences. On the 15th day of the mobilisation (that is on September 16), the French Army was to start a full scale assault on Germany. The pre-emptive mobilisation was started in France on August 26 and on September 1 full mobilisation was declared.
A French offensive in the Rhine river valley area (Saar Offensive) started on September 7, four days after France declared war on Germany. Then, the Wehrmacht was occupied in the attack on Poland, and the French soldiers enjoyed a decisive numerical advantage along the border with Germany. However, the French did not take any action that was able to assist the Poles. Eleven French divisions advanced along a 32 km line near Saarbrücken against weak German opposition. The French Army had advanced to a depth of 8 kilometres and captured about 20 villages evacuated by the German army, without any resistance. However, the half-hearted offensive was halted after France seized the Warndt Forest, three square miles of heavily-mined German territory.
The attack did not result in any diversion of German troops. The all-out assault was to be carried out by roughly 40 divisions, including one armoured division, three mechanized divisions, 78 artillery regiments and 40 tank battalions. On September 12, the Anglo-French Supreme War Council gathered for the first time at Abbeville in France. It was decided that all offensive actions were to be halted immediately. By then the French divisions had advanced approximately eight kilometres into Germany on a 24 kilometre-long strip of the frontier in the Saarland area. Maurice Gamelin ordered his troops to stop not closer than 1 kilometre from the German positions along the Siegfried Line. Poland was not notified of this decision. Instead, Gamelin informed marshal Edward Rydz-Śmigły that half of his divisions were in contact with the enemy, and that French advances had forced the Wehrmacht to withdraw at least six divisions from Poland. The following day the commander of the French Military Mission to Poland General Louis Faury informed the Polish chief of staff, general Wacław Stachiewicz, that the planned major offensive on the western front had to be postponed from September 17 to September 20. At the same time, French divisions were ordered to retreat to their barracks along the Maginot Line. The Phoney War had begun.
The open discussions on an Allied expedition to northern Scandinavia, also without consent of the neutral Scandinavian countries, and the Altmark incident on 16 February, alarmed the Kriegsmarine and Germany, by threatening iron ore supplies, and gave strong arguments for a German securing of the Norwegian coast. Codenamed Operation Weserübung, the German invasion of Denmark and Norway commenced on 9 April. On 12–15 April Allied troops were landed in Norway, but within two weeks most of Norway was in German hands and the Allied troops were evacuated from Northern Norway.
Later that day, German troops marched into Belgium, the Netherlands and Luxembourg. It was 10 May 1940, a short eight months after Britain and France had declared war on Germany. The Phoney War was over.
Most other major actions during the Phoney War were at sea, including the Second Battle of the Atlantic fought throughout the Phoney War. Other notable events among these were the following:
The warring air forces also showed some activity in that period, running reconnaissance flights and several minor bombing raids during this period. The Royal Air Force also conducted a large number of combined reconnaissance and propaganda leaflet flights over Germany. These leaflet flights were jokingly termed "Pamphlet raids" or "Confetti War" in the British press.