(Arash Khamooshi | New York Times file photo) Protestors in Tehran, Iran, burn photos of President Donald Trump and President-elect Joe Biden after Iran's leading nuclear scientist, Mohsen Fakhrizadeh, was assassinated, Nov 28. "Biden knows the region well, but if I had one piece of advice for him, it would be this: This is not the Middle East you left four years ago," writes New York Times columnist Thomas L. Friedman.