What's the current status of the Morrowind-Cyrodilic Armistice? If the Empire descended into warlords (usually called "despotism") I would presume that the Armistice would cease to have any legal/political status, notwithstanding the reformation of the Empire later. Given that, how can Morrowind still be considered part of the Empire...?

No, Morrowind has been independent of the Empire for some time, as is Black Marsh, hence why the Argonians invaded, because the Empire has no power over the Eastern provinces anymore.

As far as I am aware, Morrowind has maintained de facto independence from the Empire for some time. During the Oblivion Crisis and the Stormcrown Interregnum, the Empire withdrew its forces from Morrowind. Nor did the Empire intervene during the catastrophic events of the Red Year or the Argonian invasion that followed. For all intents and purposes, the Empire has no authority in Morrowind anymore, even if Morrowind is still considered a province of the Empire on paper somewhere.

Do you have a source for that...?

While persuasive, that doesn't mean that Morrowind is now an independent nation.

But if the Armistice is still in force, the Empire does have authority. Whether or not they have troops there is another matter. Also, AFAIK the Imperial Cult is experiencing a resurgence in Morrowind...

Dragonborn has a few things to say about Morrowind's independence.

When speaking of (now defunct) House Hlaalu:

Dragonborn also notes that the Redoran are the rulers of Morrowind in the Empire's absence, even though the House Council remains.

The only reason I pull pack from saying that Morrowind is completely independent is because we were never given a formal secession notice like there were for Black Marsh, Elsweyr, and Alinor. Therefore I'd say the most conservative position you could take on this is by saying that Morrowind maintains a de facto independence from the Empire, if not a de jure independence. That means that while the Empire might still claim for itself the right to rule Morrowind, nobody in Morrowind acquiesces to this claim.

Of course, the same could be said for all the provinces, even the provinces (except Hammerfell, who didn't leave the Empire but was cast out) that formerly declared secession from the Empire. Even with a formal secession of a nation, that doesn't mean the Empire recognizes such a secession.

OK, so what would be the likely reaction by the Empire if Morrowind gave formal notice of secession? Also, I'd disagree ever so slightly with your use of the word "defunct" to describe house Hlaalu. Wouldn't "irrelevant" be more accurate...?

The Empire sees it as a very minor problem at the moment. They've lost all but one-and-a-half provinces. And one of those provinces is in civil war and the other is largely ignoring Cyrodiil because of the Skyrim Civil War. (See Ulfric and Tullius' dialogue about High Rock's help during the unrest).

The Empire is focusing more on the hostile provinces of Elsweyr, valenwood and Alinor and the Civil War in Skyrim. It doesn't care about the destroyed Eastern province that was always unruly to begin with.

I'm playing Devil's advocate here, but why would the Empire allow Morrowind to secede given it could then mean having an enemy at their 'rear' - admittedly one with a very weak military...

Because they don't have an enemy at their rear. Morrowind was never the invading type, and they know not to mess with Cyrodiil and even only half of Skyrim. And remember, they've been crushed by the Oblivion Crisis and the Red Year and the Argonian invasion. Morrowind is very weak at the moment and only recently have they managed to drag themselves out of decline and even hope to rise again.

The Dunmer are in no position to invade, and have no desire to. They only want to rebuild, and Cyrodiil saves substantial manpower and wealth by not helping. It was cheaper and easier to let go rather than rebuilding a province that would not have helped during the great war and would have put too much Imperial power away from the real fight.

Probably vocal protest and perhaps diplomatic action. Similar to how Serbia reacted to Kosova's 2nd declaration of independence in 2008. Serbia still considers it part of Serbia, but the option for military action to make good on their claims is no longer an option (as it was after Kosova declared independence the first time in 1992). So now it sits recognized by some nations (like the U.S.) and not others (like Russia).

Irrelevant might be a better word, yeah.

The dwemer might disagree with you there...if one could be found...

Red Year was 200 hundred years ago. Surely with the threat of further Argonian invasion and the fact that Tear is still under occupation by the Argonians, the Redoran would have bolstered their military as a priority...?

I realize that but surely by the same token you could argue that Hlaalu were the 'rulers' of Morrowind before Red Year...

The Dwemer were invaded by the Nords and the Chimer. Plus, they seem to have 'misplaced' themselves.

Red Mountain was the start of a long and deep decline for Morrowind. Dialogue suggests that only during the time of the Dragonborn is Morrowind even beginning to be optimistic again. On top of everything that's happened to them, they've been isolated by the outside, having being invaded by Black Marsh and the Empire abandoning them. They're on their own, and it's pretty hard to pull yourself out of the mud when you're ear-deep in it.

Haha - I thought you might make that distinction, albeit quite a fine one... I could either assert you're splitting hairs or merely say "touche!"

I think I'll go with the latter...

What about the Emperor's attitude to an independent Morrowind? How would he react to Morrowind formally announcing independence? What do we know of his personality...?

Given that he signed the White-Gold Concordant to save the Empire from further bloodshed (and threw Hammerfell away), I imagine he'd let Morrowind go if he knew it would benefit his empire in the long run.

Ever ask yourself why the Aldmeri Dominion was resurrected after nearly a thousand years? It's because it never died, it just went underground. How could a dissident faction be so strong after so many years? Because it is ran by mer. We mer live for hundreds and thousands of years. The leaders of the Dominion today are undoubtedly the children or grandchildren of the original dissidents, if not the original dissidents themselves.

Due to our longer life cycle, we mer have a longer world view. Those of us who fled to Skyrim after the Red Year and the Argonian Invasion still live and have been waiting for the right time to return. The Empire is on the verge of collapse. The Mede Dynasty has shown it's weakness. They are powerless to stop us as we once again become the dominant race and culture in the east. They do not have the ability, or even the conviction to stop us. The Argonians will be defeated and enslaved, and we will have our independence.

Might I suggest then, that you refrain from putting such great stores of trust and faith in your heroes, who seem to have the poor habit of deserting you...

(But I did appreciate your post... )

Dissolved since the Septim Empire fell. The Mede Empire hasn't made contact with Morrowind, and most likely won't be able to reinstate something similar.

If you want a source, read the TES books about how everything just ended. After the Oblivion Crisis and sometime after Ocato's assassination, the empire just flat out fell. The Niben and Colovia split in half, and by the time Titus Mede I united Colovia and The Niben, the Empire just solely consisted of those two states of Cyrodiil (thanks to Titus Mede I reuniting Colovia and The Niben). In fact, the only time Mede bothered to help another province out was Valenwood, only because the threat of the Thalmor was highly present and he did not want to see Valenwood become an anti-Cyrodiil province and a location that would allow the hostile Thalmor to station troops at (however, that ultimately failed and the bosmer rebels were crushed). Everywhere else became de facto independant. Titus Mede I had spies in Skyrim, however he made it seem sending people there was practically a suicide mission. Somewhere, Attrebus or Titus I managed to convince Skyrim, High Rock, and Hammerfell to rejoin, but that wasn't mentioned anywhere during or after the books.

I've been avoiding reading them as I've heard they're a bit average. I might read them now, since you've prompted me...

For what its worth, the books to provide an interesting look at Tamriel that isn't in a game format, which I'm always down for.