Murder most foul. But not terrorism.
Glenn Greenwald in the Guardian has an outstanding piece entitled Was the London killing of a British soldier "terrorism"? Of course the answer to that question (his as well as mine) is "Of course not", but sadly there are plenty of people happy to call (or not to call) any killing "terrorism" if it suits their purpose. But specifically targetting a serving member of the armed forces while taking care to avoid hurt to civilians (and indeed apologising to them for making them witness the murder) is no more "terrorism" than the Fort Hood shootings were. After all, deliberately targetting soldiers and avoiding collateral damage to civilians is what the IDF claim to do, though like Barack Obama's drone strikes they seem to be less good at it than the Woolwich killers or even Nidal Hasan (who killed one civilian who charged at him while he was murdering 12 soldiers, shot only to wound when confronted with an armed civilan policewoman, and deliberately avoided shooting several other civilians). Was this guy, who deliberately targetted a civilian, a terrorost? A war criminal certainly, but not a terrorist. And how about this chap?
There are buffoons in the US Congress (OK, no shocks there....) who believe that Hasan should have been charged as a "foreign terrorist". How a Virginia-born American is "foreign", or how someone who deliberately tries to avoid civilan harm when attacking serving US soldiers is a "terrorist", is presumably something they teach you on the advanced talking-with-my-head-up-my-ass course for new Congressional representatives. Some members of Congress believe that it is necessary to define the Fort Hood shootings as an act of terrorism, or Major Hasan as a foreign combatant, in order that the dead and wounded can meet the criteria for award of the Purple Heart medal. Well, I can at least understand why they might wish that, but wishing doesn't make it so. Hasan's victims were no more wounded in combat or by terrorism than anyone else whose co-worker suddenly pulls out a gun and starts shooting. There's a reason why Fort Hood has been described as "workplace violence", and that's because it's workplace violence. Hasan didn't even have a political motivation like the Woolwich killers: he simply didn't want to deploy overseas to Afghanistan. I don't have much sympathy with that view: you sign up, you take the money, you go where they send you. But it makes him a bad soldier, not a terrorist. (I must admit I am surprised that he's still drawing his full Major's pay pending trial, but the Army say they are treating him the same way as any other soldier accused of a crime (well, not as well as Allen West, but Nidal Hasan doesn't have powerful friends in Congress to pervert the course of justice).
To return to my title: Macbeth was a murderer, and had a political motive (he wanted to be king). But he wasn't a terrorist, and not even his detractors have tried to pretend he was.