SEOUL – Even before she takes office Monday as South Korea's first female president, Park Geun-hye's campaign vow to soften Seoul's current hard-line approach to rival North Korea is being tested by Pyongyang's recent underground nuclear detonation.Pyongyang, Washington, Beijing and Tokyo are all watching to see if Park, the daughter of a staunchly anti-communist dictator, pursues an ambitious engagement policy meant to ease five years of animosity on the divided peninsula or if she sticks with the tough stance of her fellow conservative predecessor, Lee Myung-bak.Park's decision is important because it will likely set the tone of the larger diplomatic approach that Washington and others take in stalled efforts to persuade North Korea to give up its nuclear weapons ambitions.It will also be complicated by North Korea's warning of unspecified "second and third measures of greater intensity," a threat that comes as Washington and others push for tightened U.N. sanctions as punishment for the Feb. 12 atomic test, the North's third since 2006.That test is seen as another step toward North Korea's goal of building a bomb small enough to be mounted on a missile that can hit the United States. The explosion, which Pyongyang called a response to U.S. hostility, triggered global outrage.Park has said she won't yet change her policy, which was built with the high probability of provocations from Pyongyang in mind. But some aren't sure if engagement can work, given North Korea's choice of "bombs over electricity," as American scientist Siegfried Hecker puts it."Normalization of relations, a peace treaty, access to energy and economic opportunities — those things that come from choosing electricity over bombs and have the potential of lifting the North Korean people out of poverty and hardship — will be made much more difficult, if not impossible, for at least the next five years," Hecker, a regular visitor to North Korea, said in a posting on the website of Stanford University's Center for International Security and Cooperation.As she takes office, however, Park will be mindful that many South Koreans are frustrated at the state of inter-Korean relations after the Lee government's five-year rule, which saw two nuclear tests, three long-range rocket launches and attacks blamed on North Korea that killed 50 South Koreans in 2010.Agencies