The document is an abstract for a master's thesis about the contribution of third parties to the diplomatic resolution of the Iranian nuclear crisis from 2006 to 2015. It discusses US President Obama's call for coordinated international action to address global issues like non-proliferation and Iran's nuclear program. While the 2015 agreement was seen as a diplomatic success, it kept one main unresolved aspect - the decisive role played by third actors like China and Russia. The thesis aims to provide a comprehensive answer on how third parties helped resolve the crisis through constructive diplomacy, despite sometimes difficult bilateral relations.