Detailed Instructions: Given a sentence and two mentions from the text (arguments), indicate a phrase (a verb or noun phrase) that describes the relationship between the provided arguments.
Problem:Sentence: 'Al Qaeda leader Osama Bin Laden called for jihad over the Israeli offensive in Gaza in a new audio tape that appeared on Islamist websites on Wednesday .', Argument/Subject 1: 'osama bin lade', Argument/Subject 2: 'al qaeda'
Solution:
be leader of