Never heard of Nimr al-Nimr? Don't feel bad: neither did I, really, before this morning. He was a prominent Saudi Araban Shi'ite cleric... and writing 'who was in constant trouble with the Saudi Arabian regime' there would be utterly redundant, huh? At any rate, the Saudis grabbed al-Nimr in 2012, sentenced him to death in 2014, and executed him just now, presumably as part of the New Years. They say it was for terrorism-related offenses, and you may believe as much of that as you like.
That's not an empty statement, by the way. We're always in a difficult position when it comes to assessing what the Saudis have done. On the one hand, the House of Saud is the sort of dynasty that thinks that beheading and crucifixion is a perfectly reasonable punishment to hand out to seventeen year olds*. On the other hand, even tyrannical and deeply corrupt monarchies can have an opposition that's equally as awful, as we're actually seeing right now in the Middle East; and for all I know al-Nimr had indeed hidden links with unsavory Iranian-backed terrorist groups**.
And on the gripping hand? We can't just say 'Let's you and him fight;' they're fighting over what's still one of the biggest deposits of petroleum in the known world. I don't like that any more than you do, but we can't just ignore that pesky little problem, particularly since who controls the oil fields has become a serious question in the Global War on Terror.
...Do we still call it that, by the way? I'm not entirely sure that the current administration even thinks in those terms any more. And while I'd be happy enough to ask the Obama administration just how it thinks about radical Islamist terrorism - or whether it even thinks about radical Islamist terrorism at all - I'm afraid that these days the President is too busy thinking about whether he's still going to go golfing after he leaves office next year.
*Speaking generally, and not to this specific case: I personally wouldn't weep if more jihadis (even the teen-aged ones) got beheaded. When it comes to capital punishment I favor quick execution methods, largely because too much use of the slow ones does bad things to people's heads, man. But I feel that crucifixion is, to use the old Cold War phrase, nyeh kulturny.
**No, not Islamic State and/or al-Qaeda. Those are both radical Sunni groups; they would have happily executed a Shi'a apostate, although I will grant that only IS would have gone out its way to do that.