As the head of a terrorist organisation (in the eyes of the EU and US) and leader of the elected government in Gaza, Khaled Meshal is vital to any resolution of the Middle East conflict.
Operating in exile from Damascus, he has played a critical role in fraught relations with Israel and Fatah.
He is energetic in reaching out to Iran and Syria, attracting funding for welfare and education to secure Hamas's popularity in Gaza. His position encapsulates Hamas's fractured reputation: political resistance movement or militant Islamist fringe?
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