Washington (AFP) – The assassination of a top Iranian nuclear scientist, which Tehran has blamed on Israel, risks not only sharpening tensions across the region but also severely complicating plans by US President-elect Joe Biden to resume dialogue with the Islamic republic, analysts said Saturday.Iran has accused arch-foe Israel of seeking to sow “chaos” by killing 59-year-old Mohsen Fakhrizadeh and has strongly implied that the Jewish state was acting with US blessing.Washington has not officially commented on the operation, in which gunmen targeted Fakhrizadeh’s car on a road outside Tehran…