From the outbreak of the war to the signing of the treaty, the entire period amounted to only a little over two months.
If one counted only the time Germany spent fighting Poland, it was less than a month and a half.
Destroying a country with an army of over a million men in just a month and a half was inconceivable to every nation.
It had to be understood that, since no large-scale war had broken out after World War I, the primary military doctrines of every country remained stuck in the era of World War I.
Just like Poland, most countries' primary tactical doctrine was to deploy large numbers of infantry to dig trenches and fight defensive battles against the enemy head-on, while placing large numbers of cavalry on the flanks, ready to circle around and launch surprise attacks at any moment.
But the Germans changed this situation, allowing every country in the world, including the United Kingdom and France, to see a new way of waging war.
By deploying large numbers of tanks and mechanized units for rapid assaults, they could tear open a breach in the enemy's defensive line. As long as the mechanized forces were large enough and advanced quickly enough, they could completely achieve the primary objective of blitzkrieg—breaking through to the enemy's capital—before the enemy had time to react.
Of course, this kind of blitzkrieg also had certain flaws.
First, the target of a blitzkrieg could only be a country like Poland, whose territory was not particularly vast.
If the target of a blitzkrieg were a country with an extremely vast territory, such as Russia or Australasia, this tactic would place tremendous demands on logistical supplies and the size of the mechanized forces.
Second, to achieve a rapid and effective blitzkrieg, one needed