President Zia died in a plane crash in 1988, and Benazir Bhutto, daughter of Zulfikar Ali Bhutto, was elected as the country's first female Prime Minister. The PPP was followed by conservative Pakistan Muslim League (N), and over the next decade the leaders of the two parties fought for power, alternating in office while the country's situation worsened; economic indicators fell sharply, in contrast to the 1980s. This period is marked by prolonged stagflation, instability, corruption, nationalism, geopolitical rivalry with India, and the clash of left wing-right wing ideologies. As PML (N) secured a supermajority in elections in 1997, Sharif authorised nuclear testings (See:''Chagai-I'' and ''Chagai-II''), as a retaliation to the second nuclear tests ordered by India, led by Prime Minister Atal Bihari Vajpayee in May 1998.