At 9 a.m. on 3 September, Britain issued an ultimatum to Germany, demanding that Germany provide an armistice guarantee by 11 a.m., otherwise Britain would declare war on Germany. "≤, according to Sitara's interpreter, Himed, when Sitara received an ultimatum from the British, he sat still in silence. Goering, on the other hand, turned back to him and said, "If we lose this war, then God should forgive us." At noon, France issued a similar ultimatum to Germany, the deadline for which was 5 p.m. Germany ignored the ultimatum of Britain and France. As a result, Britain and France declared war on Germany one after another, and World War II broke out in full swing. That night, Sitara moved his office from the Chancellery in Berlin to the Amerika train, where he went to the front line to inspect and deal with the fighting on the Eastern and Western Fronts.

The German command, for a covert surprise attack on Poland, had deployed its troops covertly in two directions in advance. In Pomerania and East Prussia, Army Group "North" consisting of 21 divisions was assembled, under the command of the 3rd Army (Commander General Quchler) and the 4th Army (Commander Kruger, under Guderian's 19th Panzer Army), under the commander-in-chief of Von Anderson. Admiral Bock. Army Group "South" consisting of 33 divisions was assembled in German Silesia and Czechoslovakia, under the command of the 14th Army (Commander General Liszt), the 10th Army (Commander General Reichenau) and the 8th Army (Commander General Blaskovitz), with General Rundstedt under the commander-in-chief. The two clusters are supported by the 1st Air Force (commanded by General Kesselring) and the 4th Air Force (commanded by General Lehr), respectively. The German army invested a total of 44 divisions, including 7 armored divisions, 4 light armored divisions, 4 motorized infantry divisions, 1,939 aircraft, 2,800 tanks, a total of 886,000 people, including the 3,000 German ** people and their steel mounts who returned from China. The White Plan for the attack on Poland had 62 divisions and 1.6 million men if the reserves were included.

At the same time as the Amerika began to operate, on the southern Polish front, Lieutenant General Manstein and his Wehrmacht 7th Panzer Group began a beautiful right hook operation. Behind him, hundreds of "Hound Dog" 3B medium tanks, 170 "Octopus" wheeled armored vehicles, and more than 300 Sino-German joint venture Opel 10-ton six-wheeled trucks towed L21-105mm howitzers. Speaking of which, Manstein was most satisfied with this cannon, which was light in weight, simple in structure, firm and reliable, good in mobility, and equipped with more types of ammunition. The barrel is made of high-strength steel and has no muzzle brake. The large frame of the welded steel structure is a single-axis open-footed type. It was towed by trucks, and equipped with grenades, rocket extender bombs, shrapnel shells, submunitions, armor-piercing bombs, smoke bombs, chemical bombs, and flares, but the only types of munitions that were used by the Germans were the first four types of munitions, smoke grenades, and flares. But it is more than half as light as Krupp's 100-mm howitzer, has twice the range of the grenade, and can fire at a rate of up to 5 rounds per minute.

Facing the Carpathian Army Group on the west bank of the Vistula, the 7th Panzer Group was the vanguard of the 10th Army in Reichenau, and likewise the sharp knife of the entire Southern Group. On September 1

The Carpathian Army was deployed only in the Lviv region, and it was planned that they would not reach the Tarnufu region until 6 September and form a complete defensive system. Further west, in the area of Chinstokhowa and the New Mark, a group was captured, that is, the "Klakov" army, which would be attached to six infantry divisions, a cavalry brigade, and a motorized brigade. It was supposed to defend the entire Upper Silesian region and, in coordination with the Army Group "Lodz" in the Veron region, to block the advance of the German offensive group on the southern front.

In the face of the Polish army that was still on the march, the Howling Eagle swooped down with the greeting of death, and the scattered Polish army had not yet had a chance to assemble, and the fire of the 105 howitzers came unexpectedly, and after five minutes of intensive shelling, tens of thousands of soldiers could no longer return to the queue, but their comrades were not happy in the face of the steel monsters swarming in the sky.

The strength of the 7th Panzer Group was already equivalent to that of three German Panzer Divisions, and the proven technology of the Hound and Octopus kept the failure rate of the Panzer Corps below 7%, and in the face of Polish troops in the wilderness and on the road, Manstein's Panzer Corps was almost a combine harvester of life. The 45-mm 35-diameter tank gun had little chance of firing, and the sonorous sound of the 12.7-mm fire-tongued machine gun made the Polish formation sparse and confused.

By the time the "Octopus" wheeled armor rampaged to capture prisoners everywhere, the overall situation was decided for both the German and Polish armies. When Lieutenant General Manstein asked one of his tank battalions to report on the results of the battle, he received a very classic answer.

"Russia, report sir, we haven't had time to count these prisoners, we just unloaded their guns. There was no resistance in a three-kilometer radius around me, except for the dead and prisoners of war. "The power of the blitzkrieg shocked not only the conservative Polish generals, but also the German brothers, so much so that at the worst possible time, when the 7th Panzer Group had already crossed the Vistula, the main forces of the 10th Army were only 30 kilometers deep into the border.

Having broken through the Polish lines, the Germans advanced into the Polish hinterland at a speed of 50-60 kilometers per day. Rensted's Army Group South, with Reichenau's 10th Army as the main force in the center, Liszt's 14th Army as the right flank, and under the cover of the 8th Army of Blaskovice on the left flank, advanced from the west and southwest towards the middle reaches of the Vistula; Bowk's Army Group North, with Kruger's 4th Army as the main force, penetrated eastward into the "Polish Corridor", while Küchler's 3rd Army marched south from East Prussia to Warsaw and the Bug River behind Warsaw.

This is a great march of mechanized troops on a scale unprecedented in the history of human warfare. In this great march, Guderian, the founder of the German native armored army, also successfully practiced his theory of armored troops and led the 19th Panzer Army to a brilliant victory. The 19th Armored Army is subordinate to the 4th Army of Army Group North and has 1 armored division, 2 motorized divisions and 1 infantry division. It was both the middle of the 4th Army and the attacking vanguard of the Army. After the start of the war, Guderian led his troops to quickly break through the Polish border defense, crossed the Brachy River on the night of September 1, and advanced to the line of the Vistula River on September 3, completing the encirclement of the Polish army "Pomerania" in the "Polish Corridor" area. In his memoirs after the war, Guderian wrote: "By 3 September, we had formed a siege of the enemy, who was now surrounded by a forest area north of Siwiz and west of Grautunz. The Polish cavalry, because they did not understand the performance of our tanks, suffered great losses as a result. There was a Polish artillery regiment that was moving in the direction of Vestola, and on the way it was overtaken by our tanks, all of them were annihilated, and only two guns had a chance to fire. Polish infantry also suffered heavy casualties. Part of their bridge-building column was captured during the retreat, and the rest were annihilated. By September 4, all three infantry divisions and one cavalry brigade of the Polish "Pomerania" army had been annihilated, while the four divisions commanded by Guderian had only 150 dead and 700 wounded. The next day, Sitara came to inspect the 19th Panzer Corps, and Guderian, speaking to Sitara about the main experience of this operation, said: "The bravery and strength of the Poles cannot be underestimated, even surprising. But the reason why our losses in this battle were so small was entirely due to the high power of our tanks. Guderian's conclusions about the tank cluster made a deep impression on Sitara.

The German lightning attack put the Polish army completely in a situation of passive beating, which was the first time that the Poles and the world experienced the taste of "blitzkrieg". The Polish command had expected that the war would unfold slowly as usual, and that the Germans would first carry out avant-garde activities with light cavalry and then attack with heavy cavalry, and were unprepared for the "blitzkrieg" in which the Germans used a large number of tanks and aviation. British theorist Liddell. In this regard, Hart noted: "It is no exaggeration to say that they (the heads of the Polish army) are 80 years behind in their thinking. The Polish high command, overconfident in its own military power and counting on British and French assistance, deployed all its troops on the German-Polish border, believing that victory could be achieved if a resolute counterattack was carried out. This kind of deployment without strategic depth caused the Polish army to be either annihilated or divided and surrounded under the high-speed and large-depth advance of the German army, and became a lone army left behind the German army, and the resistance quickly collapsed. Although Britain and France had millions of troops on the Western Front, they did not move and declared no war. The British historian Fuller wrote: "While Poland was being annihilated, there was an amazing conflict on the Western Front. It soon became known as 'Strange War', and better known as 'Sit-down War'. "On September 6, the commander-in-chief of the Polish army, Smigli. Marshal Leeds ordered all troops to withdraw to the east of the Vistula to form the Vistula-San line. The Polish government evacuated Warsaw and moved to Lublin in a panic on the same day. The overall situation has been basically decided. Feng. Colonel Volman said to Sitara: "All that remains is to beat a rabbit, and from a military point of view, the war is over." ”

By 7 September, Rundstedt's Army Group South, which had inflicted heavy losses on the Polish armies "Lodz" and "Krakow", had occupied Lodz, the industrial center of Poland, and Krakow, the second largest city, and Manstein's 7th Panzer Group, the vanguard of the 10th Army on the Road, had rushed all the way to the southern outskirts of Warsaw on 8 September, cutting off the retreat of the Polish "Poznan" Army from the south. Bock's Army Group North completely annihilated the Polish Army Group "Pomerania" and inflicted heavy losses on the Polish Army Group "Modlin", occupied the "Polish Corridor", and then forced the Vistula River to seize the positions covering the road to Warsaw from the north.

By 8 September, Küchler's 3rd Army and Kruger's 4th Army, which belonged to Army Group North, had launched a surprise attack from the north and northwest in the general direction of Warsaw, and on 11 September, Guderian's 19th Panzer Corps crossed the Narev River and began a rapid advance towards the Bug River in the rear of Warsaw. On 14 September, Reichenau's 10th Army and Blaskowice's 8th Army, which belonged to Army Group South, surrounded the retreating Polish forces from Poznan and Lodz west of the Vistula River and occupied central Poland, leaving Warsaw in a semi-encircled state. By 15 September, Guderian's 19th Panzer Corps had encircled Brest, and his 3rd Panzer Division and 2nd Motorized Division continued to advance south in order to complete the final deep encirclement with Liszt's 14th Army, the right flank of Army Group South. At the same time, Kleist's 22nd Panzer Army, the vanguard of the 14th Army, continued its northward advance after encircling Kovov, and on 16 September joined up with Army Group North in the Vhohdava area, encircling the Polish forces that had retreated in the triangle of the Bug, San and Vistula rivers. On 17 September, the Germans, having completed the siege of Warsaw, ordered the Warsaw authorities to surrender within 12 hours. The Polish government and the Polish high command had fled across the border to Romania on 16 September.