Why is the US responsible for the success of the newly formed nation of South Sudan?

The U.S. played a crucial role in South Sudan's path to independence by providing diplomatic support, humanitarian aid, and facilitating peace negotiations during the decades-long civil war between the Sudanese government and southern rebels. American advocacy was instrumental in the 2005 Comprehensive Peace Agreement, which laid the groundwork for a referendum leading to South Sudan's independence in 2011. Additionally, the U.S. has continued to support South Sudan through development assistance and efforts to stabilize the region amid ongoing conflicts.