The Dredge Tank

I mean it worked really well until the ottoman empire stopped expanding. They operated by taking orphans from recently conquered areas and conscripting them. Once the new piece of land became more incorporated and there weren't enough orphans anymore they'd have to move on to the next place. Once expansion stopped for a long enough period of time they had to reform the Janissaries into a hereditary organization which both eroded their effectiveness in battle, and gave them political power.

Basically every single Ottoman institution was based around the assumption of conquest. And, to be fair, they continually expanded their borders for 400 years. Their decline took another 200 years after that. Liberal capitalism is only 200 years old and its already starting to decline so the ottomans were pretty baller by comparison.

i think mamluks and the separation of military and interior concerns within various Islamic states of the period are very interesting developments tbh. it was a very interesting aspect of reading Debt. part of the core notion there was hacking around the no muslims killing muslims rule in Islam. what do you do when the other caliphate has shit you want? simply send our christian slave army to fight them of course! but then, this also is the kind of thing that allowed the interesting proto-capitalist economy based on mutual cooperation to come into existing, and the islamic world to innovate checks that could be written in Mali and cashed in Iran. especially this is interesting when you compare it to the 10's of thousands of tiny feudal territories that Europe was carved into at the same time.