Step 1: Understanding the Concept:
Global conservation policies are guided by international non-governmental and governmental organizations.
These bodies assess the conservation status of species worldwide.
Step 2: Detailed Explanation:
IUCN stands for the International Union for Conservation of Nature (officially the International Union for Conservation of Nature and Natural Resources).
Founded in 1948, it is the world's largest global environmental network.
It is widely recognized for publishing the Red List of Threatened Species, which categorizes species based on their extinction risk.
Step 3: Final Answer:
The correct expansion of IUCN is the International Union for Conservation of Nature.