List of agreements between two states, two blocs or a bloc and a state. Political groups and parliamentary voting blocs exist, although most candidates run as independents. In Europe, two opposing hostile imperialist blocs had formed. Attempts to return to proportional representation with open party lists and electoral blocs were failed. Two distinct political blocs formed amongst the 30 elected members. These groups organized voting blocs that dominated the 2015 Hugo Awards. Only members of the majority and minority blocs are accorded committee memberships. These nations also take part in inter-continental trade blocs. The major trade blocs (or agreements) in the region are the Pacific Alliance and Mercosur. Six left parties fought jointly, independently from both of the two main blocs. Yugoslavia's non-aligned status resulted in access to loans from both superpower blocs. A global political system based on international agreements and supra-national blocs characterized the post-war era. These actions were precipitated by ad hoc, leaderless, anonymous cadres known as black blocs. Serbia has a wide-range of free trade agreements with foreign countries and trading blocs. Many advocates of global free trade are opposed to trading blocs.