Briefly describe the reasons for Spain's gradual decline from the end of 16.

A: First, in the16th century, on the one hand, Spain was often involved in dynastic wars and religious wars on the mainland, on the other hand, it carried out many naval wars, thus dispersing its forces. This is in stark contrast to the policy pursued by Britain later: Britain does not intervene in the affairs of the European continent, but only when the balance of power in the mainland is threatened. This policy made it possible for Britain to concentrate on overseas colonial expansion. Second, Spain's rule and restrictions on the colonies were too strict, which hindered the industrial and agricultural development and population growth (immigration) of the colonies, so that Spain could not get strong help from the colonies in the hegemonic war. Third, Spain's backward industry leads to weak national strength, which makes Spain lack economic backing in the hegemony war.