Operation Citadel (German: "Unternehmen Zitadelle" ) was a German offensive operation against Soviet forces in the Kursk salient during the Second World War on the Eastern Front that initiated the Battle of Kursk.
 The deliberate defensive operation that the Soviets implemented to repel the German offensive is referred to as the Kursk Strategic Defensive Operation.
 The German offensive was countered by two Soviet counter-offensives, Operation Polkovodets Rumyantsev (Russian: Полководец Румянцев ) and Operation Kutuzov (Russian: Кутузов ).
 For the Germans, the battle was the final strategic offensive that they were able to launch on the Eastern Front.
 As the Allied invasion of Sicily began Adolf Hitler was forced to divert troops training in France to meet the Allied threats in the Mediterranean, rather than use them as a strategic reserve for the Eastern Front.
 Germany's extensive loss of men and tanks ensured that the victorious Soviet Red Army enjoyed the strategic initiative for the remainder of the war.
The Battle of Château-Thierry was fought on July 18, 1918 and was one of the first actions of the American Expeditionary Forces (AEF) under General John J. "Black Jack" Pershing.
 It was a battle in World War I as part of the Second Battle of the Marne, initially prompted by a German offensive launched on 15 July against the AEF, an expeditionary force consisting of troops from both the Army and Marine Corps, and the newest troops on the front.
The Battle of Pusan Perimeter was a large-scale battle between United Nations and North Korean forces lasting from August 4 to September 18, 1950.
 It was one of the first major engagements of the Korean War.
 An army of 140,000 UN troops, having been pushed to the brink of defeat, were rallied to make a final stand against the invading North Korean army, 98,000 men strong.
The Nivelle Offensive of 1917, was a Franco-British offensive on the Western Front in the First World War.
 The French part of the offensive was intended to be strategically decisive, by breaking through the German defences on the Aisne front within 48 hours, with casualties expected to be around 10,000 men.
 A preliminary attack was to be made by the French Third Army at St. Quentin and the British First, Third and Fifth armies at Arras, to capture high ground and divert German reserves from the French fronts on the Aisne and in Champagne.
 The main offensive was to be delivered by the French on the Chemin des Dames ridge (the Second Battle of the Aisne, "La bataille du Chemin des Dames" , "Seconde bataille de l'Aisne" and "Doppelschlacht Aisne-Champagne" ), with a subsidiary attack by the Fourth Army (the Third Battle of Champagne, the Battle of the Hills or Battle of the Hills of Champagne).
 The final stage of the offensive was to follow the meeting of the British and French armies, having broken through the German lines, with a pursuit of the defeated German armies towards the German frontier.
The Second Battle of the Marne (French: "Seconde Bataille de la Marne" ), or "Battle of Reims" (15 July – 6 August 1918) was the last major German offensive on the Western Front during the First World War.
 The attack failed when an Allied counterattack by French and American forces, including several hundred tanks, overwhelmed the Germans on their right flank, inflicting severe casualties.
 The German defeat marked the start of the relentless Allied advance which culminated in the Armistice with Germany about 100 days later.
The Second Battle of Naktong Bulge was an engagement between United Nations (UN) and North Korean (NK) forces early in the Korean War from September 1 to September 15, 1950, along the Naktong River in South Korea.
 It was a part of the Battle of Pusan Perimeter, and was one of several large engagements fought simultaneously.
 The battle ended in a victory for the United Nations after large numbers of United States (US) and Republic of Korea (ROK) troops repelled a strong North Korean attack.
The Battle of the Bulge (16 December 1944 – 25 January 1945) was the last major German offensive campaign on the Western Front during World War II.
 It was launched through the densely forested Ardennes region of Wallonia in eastern Belgium, northeast France, and Luxembourg, towards the end of World War II.
 The surprise attack caught the Allied forces completely off guard.
 American forces bore the brunt of the attack and incurred their highest casualties of any operation during the war.
 The battle also severely depleted Germany's armored forces, and they were largely unable to replace them.
 German personnel and, later, Luftwaffe aircraft (in the concluding stages of the engagement) also sustained heavy losses.
The Battle of the Marne (French: Première bataille de la Marne , also known as the Miracle of the Marne, "Le Miracle de la Marne") was a World War I battle fought from 6–10 September 1914.
 It resulted in an Allied victory against the German armies in the west.
 The battle was the culmination of the German advance into France and pursuit of the Allied armies which followed the Battle of the Frontiers in August and had reached the eastern outskirts of Paris.
 A counter-attack by six French armies and the British Expeditionary Force (BEF) along the Marne River forced the Imperial German Army to retreat north-west, leading to the First Battle of the Aisne and the Race to the Sea.
 The battle was a victory for the Allies but led to four years of trench warfare stalemate on the Western Front.
Operation North Wind (German: "Unternehmen Nordwind" ) was the last major German offensive of World War II on the Western Front.
 It began on 31 December 1944 in Alsace and Lorraine in northeastern France, and ended on 25 January.
The Hindenburg Line ("Siegfriedstellung" or Siegfried Position) was a German defensive position of World War I, built during the winter of 1916–1917 on the Western Front, from Arras to Laffaux, near Soissons on the Aisne.
 In 1916, the German offensive at the Battle of Verdun had been a costly failure.
 The Anglo-French offensive at the Battle of the Somme had forced a defensive battle on the Germans, leaving the western armies ("Westheer") exhausted.
 On the Eastern Front, the Brusilov Offensive had inflicted huge losses on the Austro-Hungarian armies in Russia and forced the Germans to take over more of the front.
 The declaration of war by Romania had placed additional strain on the German army and war economy.
 Construction of the Hindenburg Line in France was begun by the Germans in September 1916, to make a retirement from the Somme front possible, to counter an anticipated increase in the power of Anglo-French attacks in 1917.

Question: What was the last major German offensive on the Western Front during the First World War, Second Battle of the Marne or Battle of Pusan Perimeter?
Answer: Second Battle of the Marne