The addition of a nuclear sub to the attack group implies the ability to move directly to full scale nuclear war.
I don't think so. The point of nuclear armed subs is that they can lob their nukes from anywhere. I don't see what is added by being local.
And of course the point of them is that you don't know where in the world they are so the only point in telling people is to ramp up psychological pressure.
Any nuke ever used (God help us!) would be a bomb delivered by plane, I suspect, or a cruise missile. "Any economic unit can emit money. The serious problem is to get it accepted" Hyman Minsky
No major power in their right mind would transit a ballistic armed sub through the canal on the off chance that that a local power decided to take a quick route to Nuclear weapon armed status, I think we can safely say that it's one of the little ones, of which there are probably two or three in the area already. Any idiot can face a crisis - it's day to day living that wears you out.
There is no worry at all about Egypt hi-jacking a sub. When our puppet government in Cairo joins the Islamic suicidists, then there might be cause. The Fates are kind.
Deployment of an SSGN would be news, but you will never know: they rotate crews in Diego, pretty close, no canal to the gulf, no port visit.
Right now, I think 3 SSGN are up, one is on port visit in south korea, one just received a new crew in diego in the past week. Maximum 2 on location in the coming weeks. Pierre
What is added is reduction in time. The attack will have to go VERY fast. Close placement enables this. The Fates are kind.