Resource and knowledge flows that were direct consequences of military expenditures and the empires they built were essential in both cases.
> The causality may run in reverse.
The causality absolutely and unquestionably runs in both directions; in both cases the economic revolutions were processes fueled by an fueling military-expenditure-dependent empires.
Can't agree to that. As noted, correlation isn't causality from or consequence thereof. Wikipedia's list of critical tech for industrial revolution is textiles, steam power, iron working, machine tools. That seems reasonable. In context, the key developments of all happened upstream of military use/development (although they had military use, military expenditures were not causal).
Take Watt's steam engine improvements. The development was substantially if not entirely civilian. Ran water pumps for coal mining which supported many industries including military, and military use was not critical for development.
Possible counter example is Harrison's marine chronometer. Development was militarily supported and spurred on by a naval disaster. However, while contributory, wasn't essential to success of industrial revolution.
https://en.wikipedia.org/wiki/Industrial_Revolution#Importan...
https://www.goodreads.com/en/book/show/34959327-the-wizard-a...