Elected in December, Park also must answer victims of her father's 18-year dictatorship and address worries about a lack of jobs, a growing gap between rich and poor and a stagnant economy. There's pressure for her to live up to her campaign suggestion that she can return the country to the strong economic growth her father oversaw, the so-called Miracle on the Han River.
North Korea's underground atomic detonation tests her vow to soften Seoul's current hard-line approach to its northern rival. Park called the Feb. 12 test, the North's third since 2006, "a challenge to the survival and future of the Korean people" and said Pyongyang should abandon its nuclear ambitions and work for peace.
"There should be no mistake that the biggest victim will be none other than North Korea itself," Park said in her first speech as president during a ceremony where troops in formal uniforms shouted "loyalty" and fired cannons in salute.
At her inauguration, a band played a military march before a crowd of tens of thousands, including U.S. National Security Adviser Tom Donilon, Thai Prime Minister Yingluck Shinawatra and Japanese Deputy Prime Minister Taro Aso. Before Park took her oath of office, South Korean superstar PSY performed his global hit "Gangnam Style." Children and the elderly alike joined him in the contagious horse-riding dance he made famous in the song's video.