Final answer:
The Commonwealth of Independent States (CIS) is a contemporary example of an international confederal system, consisting of former Soviet Union states that cooperate while retaining significant sovereign powers.
Step-by-step explanation:
A good modern day example of an international confederal system is the Commonwealth of Independent States (CIS). This organization consists of nations that were formerly parts of the Soviet Union. They have formed a partnership that focuses on mutual cooperation. The central authority is relatively weak, with each member retaining much of their sovereign powers such as maintaining military forces, printing money, and making treaties. In contrast, federations like the United States and unitary states like Japan possess different distributions of power between central and subordinate levels of government, offering varied degrees of autonomy. However, it is important to note that recent trends indicate federal systems are more prevalent than unitary systems globally.