Why did the United States of America allow the states and territories to have their own military, the militia, the ancestor of the national guard of today?
Why did Great Britain allow the thirteen colonies to have their own military, the colonial militia, even during the years of tension leading up to the Revolution, the years when the British government might fear that the militias of the colonies might be used to fight against Great Britain?
Why did the United States government allow Indian tribes, with status similar to states and territories, to keep their own military forces, roughly similar to the militia, for years or decades after those tribes signed treaties making them subordinate parts of the United States?
Why did medieval kings allow their nobles to have their own military forces, knights who owed military service to those nobles? Why did nobles allow lesser nobles subordinate to them to have their own military forces, knights who owed them military service?
Why did Mark Antony allow his subordinate, Cleopatra, Queen of Kings, to have her own military and naval forces?
Why did the German Empire of 1871-1918 allow the member kingdoms and states to have their own armed forces which were under joint imperial/state control?
Why did medieval kingdoms allow orders of chivalry such as the Knights Hospitalar, the Teutonic Knights, and the Templars to have their own estates and castles and armed knights in the territories of those kingdoms?
Why did the Chinese emperors allow the kings of Korea to have their own military?
Why did the Tokugawa Shoguns allow the daimyo to have their own samurai military forces?
Why did Great Britain allow trading corporations like the Nigeria Company and the East India Company to have their own armed forces and gain territorial possessions?
Why did the Netherlands allow trading companies like the East India and West India companies to have armed forces and gain territorial possessions?
Why did the Mughal Padishah allow European trading companies like the British and French East India Companies to maintain their own armed forces and gain territorial possessions?
And perhaps most significant, why did the Holy Roman Empire allow the Hanseatic League to have its own military and naval forces and fight wars?