In June 2013, President Obama met with President Xi Jinping at Sunnylands, California. The meeting was seen as a chance for the two leaders to get to know each other in a relatively informal setting so they could address the growing mistrust between their countries. While maritime disputes, trade tensions and differences over how to contain the North Korean and Iranian nuclear programmes were high on the agenda, cyber security—in particular Chinese cyber espionage—was the defining issue of this unusual summit.