Terrorist atrocities. A war against all Arab governments. A particular preference for attacks and stunts involving airliners. Extracting money from Saudi Arabia. And actual support for Saddam Hussein, not just the imagined type.
Not Osama bin Laden. George Habash, probably the last remnant of the days when Palestinian extremism had little to do with holy war as it's now thought of.
But Habash died an old man, witnessing the defeat of just about every cause he cared about. Perhaps because there wasn't a George Bush to validate the worst assumptions of his followers and make him an iconic figure.
It seems that he was Marxist-Leninist to the end. It'll be interesting to see if Christopher Hitchens marks his death.