The interaction of a number of factors allowed a small corner of North-Western Europe to remain in revolt against a super-power, and eventually gain independence for some of the provinces.
<Tab/>The Netherlands was a very hard country to attack; with numerous large rivers, swamps and many walled towns; each of which required a pro-longed siege to capture. As a result, it was very hard for the Spanish to made progress in the Netherlands; and progress that was made would come at a great cost and over a lengthy period of time as a result. However, this did not provide an insurmountable obstacle: regardless of Dutch defences, the Spanish were able to re-conquer much of the Netherlands under Parma. Military considerations and underlying economic considerations therefore had a much larger impact on the outcome of the revolt; one can see that the final stale-mate position that Parma reached was along an arbitrary military line rather than any geographical feature. Moreover, had Spain had full access to its resources as a super-power, there is little doubt that it would have crushed the revolt with the vastly superior resources potentially at its disposal regardless of any Dutch defence.
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