By NBC's Sarah Blackwill For months, it's been Bill Clinton who's been building his legacy as a go-to surrogate for the president, taking on a mushrooming role as "secretary of explaining stuff," working big donors, testifying to his former rival's leadership qualities. But don't overlook the importance of tonight's debate, and the days that follow, for the other Clinton legacy. Hillary Clinton will once again be at the center of a presidential debate, but this time it's in her role as Secretary of State. Tonight, President Obama and Mitt Romney clashed for first time in person on the president's handling of the September 11 Libya attack. At stake are not just perceptions of Obama's foreign policy and commander-in-chief credentials, but Clinton's diplomatic legacy. Clinton's approval ratings in national polls hover around 70 percent. Although her husband has been more bullish on a 2016 run than she has, WWHD - What Will Hillary Do? - speculation will only get louder once she leaves the State Department at the end of the president's first term.Traveling in Lima, Peru Monday, Clinton took responsibility for the security decisions that were made leading up the attack on the U.S. consulate in Benghazi. But the flurry of television interviews were her first since the attack. Clinton didn't issue a 'Buck Stops at Foggy Bottom' mea culpa after the vice president argued in last Thursday's debate, "We weren't told they wanted more security,” a statement the White House later said referred just to Biden and the president. Her public schedule was notably quiet in the weeks when Ambassador Susan Rice, one of the candidates to replace her at State, was heavily criticized for providing misinformation after the attack. What will the debate over security lapses in Libya - and the politics that ensue - mean for Clinton's legacy? Check out highlights from Secretary Clinton's interviews abroad.