Explanation: The Phoney War, a period of relative military inactivity on the Western Front, spanned approximately eight months, from September 1939 to May 1940.

Explanation: While World War II began with the invasion of Poland on September 1, 1939, the formal declarations of war by the United Kingdom and France against Germany occurred on September 3, 1939, marking the commencement of the Phoney War period.

Explanation: The initial British term for the period of inactivity was 'Bore War.' The term 'Phoney War' gained prominence later, partly due to American usage.

Explanation: U.S. Senator William Borah is widely credited with popularizing the term 'Phoney War' to characterize the perceived lack of substantial military engagement on the Western Front.

Explanation: While the war was declared, interactions between soldiers on opposing sides during the Phoney War were not consistently hostile, with some instances of surprisingly cordial or neutral encounters reported.

Explanation: The term 'Western betrayal' typically refers to the perceived failure of the Western Allies to provide adequate military support to Poland during its invasion, a criticism leveled during the Phoney War period.

Explanation: The defining characteristic of the Phoney War was the absence of significant land combat operations between the main Allied and German forces on the Western Front.

Explanation: The Phoney War period commenced on September 3, 1939, with the formal declarations of war by the United Kingdom and France against Germany, following Germany's invasion of Poland.

Explanation: The initial British term used to describe the period of inactivity was 'Bore War,' a pun on the earlier Boer War. The term 'Phoney War' gained wider acceptance, partly due to American usage and its descriptive nature.

Explanation: U.S. Senator William Borah is widely credited with coining or popularizing the term 'Phoney War' to describe the perceived lack of genuine conflict on the Western Front.

Explanation: In French, the period of inactivity was referred to as 'drôle de guerre,' which translates to 'funny' or 'strange' war.

Explanation: The term 'Western betrayal' is often used to describe the perceived lack of substantial military support provided by Britain and France to Poland following the German and Soviet invasions.

Explanation: Contrary to large-scale land offensives, the Western Allies adopted a largely defensive posture on the Western Front during the Phoney War, focusing instead on economic warfare and resource build-up.

Explanation: During the Phoney War, the RAF's aerial activities over Germany were largely restricted to reconnaissance and propaganda leaflet flights, not direct bombing raids on cities, due to strategic caution and a proposed bombing ban.

Explanation: German commanders assessed that their Western Front forces were lightly defended during the Polish invasion and believed they could only have withstood a major French offensive for a short period.

Explanation: The Allied naval blockade was implemented to restrict Germany's access to essential food and raw materials, thereby hindering its war-making capacity.

Explanation: The Franco-Polish Alliance stipulated that the French Army would commence preparations for a major offensive three days after mobilization, with the full assault planned for the 15th day.

Explanation: Despite the inactivity on the Western Front, the Allies engaged in economic warfare, notably implementing a naval blockade to restrict Germany's imports and disrupt its war economy.

Explanation: While the Allies formulated plans for interventions in the Balkans and Norway, and considered embargoes against the Soviet Union, a full-scale invasion of Germany in September 1939 was not a realistic or formulated plan.

Explanation: The Allied strategy during the Phoney War involved maintaining a defensive posture on the Western Front to allow for resource build-up and strategic preparation.

Explanation: Due to strategic caution and a proposed international ban on bombing, the RAF's aerial operations over Germany during the Phoney War were primarily limited to reconnaissance and the dropping of propaganda leaflets, rather than direct attacks on cities.

Explanation: The primary objective of the Allied naval blockade was to prevent Germany from importing essential food and raw materials, thereby crippling its war economy and capacity.

Explanation: The Altmark incident occurred when the Royal Navy boarded the German tanker Altmark in Norwegian territorial waters, not Swedish, to free British prisoners of war.

Explanation: Contrary to the statement, significant naval actions, such as U-boat attacks on Allied shipping and surface engagements like the Battle of the River Plate, did occur during the Phoney War.

Explanation: The RAF's early daylight bombing raids on German warships were largely unsuccessful and resulted in significant bomber losses, leading to a reassessment and shift away from such operations.

Explanation: Following the Battle of the River Plate, the Admiral Graf Spee was not captured by the British; instead, its crew scuttled the vessel in Montevideo harbor to avoid capture.

Explanation: Operation Wikinger was a German destroyer sortie into the North Sea that resulted in the loss of two destroyers due to mines and friendly fire, causing significant casualties.

Explanation: The Battle of the River Plate was a surface engagement between British cruisers and the German pocket battleship Admiral Graf Spee, not primarily involving U-boats attacking supply lines.

Explanation: The sinking of the British aircraft carrier HMS Courageous by the German submarine U-29 on September 17, 1939, was indeed a significant early success for German U-boats during the Phoney War.

Explanation: The sinking of HMS Royal Oak occurred due to a torpedo attack by the German submarine U-47 while the battleship was at anchor in the Scapa Flow naval base, not during an air raid.

Explanation: The Luftwaffe's raid on Rosyth on October 16, 1939, did result in losses for the German aircraft, with British air defenses successfully downing several bombers.

Explanation: The Battle of the River Plate in December 1939 was a significant naval engagement that occurred during the Phoney War period.

Explanation: The RAF's initial daylight bombing raids against German warships proved to be costly failures, resulting in substantial bomber losses and prompting a reconsideration of aerial tactics.

Explanation: Following damage sustained in the Battle of the River Plate and seeking refuge in Montevideo, the Admiral Graf Spee was scuttled by its crew in December 1939 to prevent its capture.

Explanation: Operation Wikinger was a German destroyer sortie into the North Sea intended to disrupt British fishing and submarine activities, but it resulted in significant losses due to mines and friendly fire.

Explanation: The Battle of the River Plate was a key naval engagement that ultimately led to the scuttling of the German pocket battleship Admiral Graf Spee by its own crew.

Explanation: The British battleship HMS Royal Oak was sunk by the German submarine U-47 in the Scapa Flow naval base on October 14, 1939.

Explanation: Plan West, the Polish defense strategy, was predicated on the assumption that the Western Allies would initiate a substantial offensive on the Western Front to divert German forces.

Explanation: The French Saar Offensive was a limited operation, advancing only a few kilometers into evacuated German territory and capturing villages, rather than penetrating deeply or capturing major cities.

Explanation: The Saar Offensive was strategically ineffective and failed to divert any significant German forces from the Polish Front.

Explanation: Operation Weserübung was the German codename for the invasion of Denmark and Norway, launched on April 9, 1940, not the invasion of Poland.

Explanation: The Allied campaign in Norway did not conclude with a decisive victory; Allied forces were eventually evacuated, and Norway surrendered to German forces.

Explanation: A primary objective of the Allied plan to invade Norway was to secure control over Germany's vital iron ore supplies, which were crucial for its war industry.

Explanation: Allied discussions regarding potential intervention in Scandinavia prompted Germany to accelerate, rather than delay, its invasion plans for Denmark and Norway to preempt Allied action and secure strategic resources.

Explanation: The primary strategic objective of the French Saar Offensive was to draw German forces away from the Polish Front, thereby alleviating pressure on Poland.

Explanation: Operation Weserübung was the codename for Germany's invasion of Denmark and Norway, commencing on April 9, 1940.

Explanation: The Soviet invasion of Finland in the Winter War generated considerable public sympathy and support for aiding Finland among the British and French populations, influencing political discussions.

Explanation: Following its unprovoked invasion of Finland, the Soviet Union faced international condemnation and was expelled from the League of Nations, not praised.

Explanation: Édouard Daladier's resignation as Prime Minister of France in March 1940 was influenced, in part, by public and political dissatisfaction with his government's inability to effectively support Finland during the Winter War.

Explanation: The Soviet Union assisted Germany in circumventing the Allied naval blockade by supplying crucial goods, thereby mitigating the blockade's economic impact on Germany.

Explanation: The Winter War generated significant public sympathy for Finland in Britain and France, leading to discussions about intervention and influencing Allied strategic considerations.

Explanation: As a direct consequence of its invasion of Finland, the Soviet Union was expelled from the League of Nations in December 1939.

Explanation: The Soviet Union's provision of goods to Germany helped it circumvent the Allied naval blockade, thereby diminishing its overall effectiveness.

Explanation: The period of inactivity known as the Phoney War definitively ended on May 10, 1940, with the commencement of Germany's invasion of France and the Low Countries.

Explanation: Winston Churchill assumed the role of Prime Minister of the United Kingdom on May 10, 1940, the same day Germany launched its invasion of France and the Low Countries, marking the end of the Phoney War.

Explanation: The military and political fallout from the unsuccessful Allied campaign in Norway directly contributed to Prime Minister Neville Chamberlain's resignation on May 10, 1940.

Explanation: The Phoney War concluded on May 10, 1940, with the commencement of Germany's invasion of France and the Low Countries, shattering the period of inactivity.

Explanation: The military and political repercussions of the unsuccessful Allied campaign in Norway were a primary factor leading to Prime Minister Neville Chamberlain's resignation on May 10, 1940.