The commitment made by US President Barack Obama and Chinese leader Xi Jinping at the June 2013 Sunnylands Summit in California to forge a “new type of major country relations” between the United States and China has set a highly positive tone for the bilateral relationship. It has provided a useful framework to advance US-China cooperation (and better manage competition) on a range of issues, including in the strategic nuclear field where key disagreements persist and where there is still no official bilateral dialogue.