In 1993, Sani Abacha seized power in a military coup. Openly critical of Abacha's administration, in 1995 Obasanjo was arrested and convicted of being part of a planned coup, despite protesting his innocence. While imprisoned, he became a born again Christian, with providentialism strongly influencing his subsequent worldview. He was released following Abacha's death in 1998. Entering electoral politics, Obasanjo became the PDP candidate for the 1999 presidential election, which he won comfortably. As president, he de-politicised the military and both expanded the police and mobilised the army to combat widespread ethnic, religious, and secessionist violence. He withdrew Nigeria's military from Sierra Leone and privatised various public enterprises to limit his country's spiralling debt. He was re-elected in the 2003 election. Influenced by Pan-Africanist ideas, he was a keen supporter of the formation of the African Union and served as its chair from 2004 to 2006. Obasanjo's attempts to change the constitution to abolish presidential term limits were unsuccessful and brought criticism. In retirement, he earned a PhD in theology from the National Open University of Nigeria.