I feel as though this is an important question for me to ask before I presume it.

What with the breakup of the United States and the federated EU's poor economic and financial status, can it then be assumed that Great Britain is the post-war world's financial leader, and the pound sterling the international reserve currency? I intend on making my state more or less a direct, logical continuation of the present day United Kingdom, taking the drastic changes in the international world into account.