Palestinian President Mahmoud Abbas (left) and Khaled Mashal, chief of Hamas (right), sit with Qatari Emir Sheikh Hamad Bin Al-Khalifa Al-Thani, as they sign a reconciliation agreement in Doha, Monday. The main Palestinian political rivals took a major step toward healing their bitter rift, agreeing that Abbas would head an interim unity government to prepare for general elections in the West Bank and Gaza.