Its when change is like pew pew and when things gop
<span>The United States Constitution divides foreign policy powers between the President and the Congress so that both share in the making of foreign policy. The executive and legislative branches each play important roles that are different but that often overlap. Both branches have continuing opportunities to initiate and change foreign policy, and the interaction between them continues indefinitely throughout the life of a policy. This report reviews and illustrates 12 basic ways that the United States can make foreign policy. The practices illustrated in this report indicate that making foreign policy is a complex process, and that the support of both branches is required for a strong and effective U.S. foreign policy. For a detailed discussion of how war-making powers are shared, see War Powers Resolution: Presidential Compliance.</span>
Okay one big reason, you don't have to go further then Hitler. The "cause" to his power was because of the political failure of the Wiemar Public which was imposed on Germany in 1919.
Hope I got it correct!
C. The large migration of a group of people
