Hello. Do you think that Protect action can be used against a Threaten attack ?
(We can imagine the player interjecting himself into the conversation, cutting off speech…)
As the Protect Reaction is stated in the core rules, it is only against an “attack”, that means, of ANY type - which would include Threaten attacks as well.
I see the general application of this a bit critical regarding plausibility.
If you have a scene where an opponent gives a lengthy speech threatening one of the PCs another PC might plausibly interject and verbally protect the threatened other PC.
But often you have the basic “steely glare”, that is a simple look with murder in the eyes. I cannot see how another PC would protect the targetted one from this threaten attack which actually happens in the blink of an eye.
So I would rule this on a case by case basis, governed by plausibility and time the actual threaten attack might have taken.
And: that works the other way around, too! - If a PC with high Renown tries to subdue by reciting his deeds for the A Mighty Name Display, another NPC might as well step in and try to protect the original target by explaining that names are just words, nothing more. (Also a Discipline test, as usual - and at +1 Difficulty, making the interposing NPCs the new target - just as with the Protect Reaction for other forms of attacks.)