Help to understand some phrases in the sentence

Question

I don't quite understand some phrases in this sentence.

President Donald Trump has responded to provocations from the reclusive nation with bombastic rhetoric, at one point threatening North Korea with "fire and fury." 

1. At one point threatening North Korea with "fire and fury" -- Is it an adverbial phrase as a whole? If yes, what's it modifying?
2. Does 'at one point' here mean 'at one hand'?
3. 'fire and fury' I got an explanation for this phrase from a website as below. But still not quite get it. Can someone give a brief or more easier way to understand it?

“Fire and Fury” is the 2017 administration’s rendition of “Shock and Awe”. It is a pithy way of conveying that you intend to use considerable overwhelming military force to accomplish a given objective. The advantage of a phrase like this is that it is not very definitive. So, there is plenty of wiggle room as to what constitutes ‘fire and fury’, in the event of hostilities. It sounds sooooo much more elegant than “we’ll shoot back” or “we’re gonna bomb you”. Plus, it’s fodder for CNN commentators. They can scratch their chins and opine as to just exactly what constitutes the Trump administrations F&F policy. It makes for great entertainment all around!

By the way, what's the meaning of "scratch their chins" in the above quote?

Answer 1

Answer part 1) Using a phrase like, "fire and fury" has a long history in the English language. You'll see pairs like this used over and over, especially in legal language, where they're called "legal doublets."

The reason this happens is because back in the year 1066 France invaded England and took the place over. This created a situation where most of the ruling class spoke French or Latin, and most of the peasants spoke Anglo Saxon. In order to be understood clearly, they'd often pair a French word with an Anglo Saxon word, and eventually it became a common way of speaking to combine synonyms to emphasize a point.

Some common pairs are:

plain and simple

peace and quiet

neat and tidy

over and above

Answer part 2) "At one point" in this context is referencing the fact that Trump has made more than one statement, and in one of them he made the fire and fury comment.

Using the word, "Hand" generally implies two sided statements that contradict themselves. You have two hands... a right and a left. You have two opinions - you like someone, and you hate someone.

In this case Trump is not going back and forth between loving and hating the North Koreans, so using the word "hand" wouldn't fit.

Answer part 3) Again, "fire and fury" are word pairs that imply a certain type of military action - here they're basically implying that the US will destroy everything without holding themselves back.

Answer part 4) Scratch their chins. If you're scratching your chin, it usually implies that you're thinking about and considering something. Trump said, "fire and fury." Did he really mean he'd nuke the whole place, or does he mean something else? What did Trump really mean when he said, "fire and fury?" Nobody really knows except for Trump and so the commentators can only guess what he really means.