1. Tullius invites the Thalmor agent Elenwen to the truce negotiation.
2. Elenwen claims she has every "right" to be present, to ensure nothing is agreed to that violates the concordat. But she really doesnt. The concordat does not specify Thalmor rights to be present at any meeting they presume to want to, or else she would have said that and insisted on it.
3. Tullius claims "She is part of the Imperial delegation"

So, Tullius views the Thalmor (or at least Elenwen) as allies. Why is that? What does he hope to gain by having the Thalmor sit in on negotiations? Did he hope that Elenwen could use Thalmor magic to influence the talks, or to gather intelligence? Or are they romantically involved perhaps?

I think, that like the rest of the Empire now, Tullius is the Thalmor's [censored]. Like the rest of the Empire, he's too scared to stand up to them. That's why he makes excuses for her to join in the talks.

I think 2 is shaky. We don't know much about the White Gold Concordat at all, other than the banishing of Talos worship.

Tulius hates the Thalmor. However the Thalmor have to get thier ugly faces involved in every single thing and Tulius cannot be botherd to deal with politics.
Or maybe it was to annoy Ulfric.

Most likely, this.

Well after the Great War and the Empire win after the Battle of the Red Ring, a truce was formed with the signing of the White-Gold Concordat signed by both the Imperial Legion (Empire) and the Aldmeri dominion with the agreement of the banning of Talos, the Blades to be outlawed and Thalmor control of southern Hammerfell.

Even though the Empire won they were very weak compared to the Aldmeri Dominion so they had to make sure they were allied with them inviting them to meetings to make sure nothing that involved overruling of the agreement was made.

I don't know, but I wish we could kill her.

He hates them, but the empire is not ready to go for round 2 with the thalmor just yet.

It sure didnt sound like he hated them when he defended her presence. That didnt sound like he hated her at all.

Why would he want to sound like he hates her? It's better for his negotiating position if he doesn't make it obvious.

Ok that goes to the original posted question. How exactly does it improve his negotiating position? What did he gain? Afaict he gained nothing at all from it.

It's not so much about what he gains from acting like he doesn't hate them, but what he would lose by admitting that he hates them. Especially in front of Elenwen and Ulfric. Speaking to that particular situation, it's no secret that Tullius doesn't want Elenwen there either, but it's in his best interests to keep the Thalmor on good terms for the time being, until the Skyrim situation is resolved. It's a little thing called diplomacy.

My guess is that Baldy is trying to provoke Ulfric, maybe into using the thu'um or doing something else that would discredit his cause.

When a nation loses a war, the winner isn't just going to leave peacefully and keep their new lands. They always, ALWAYS leave some sort of an occupation force or a committee to make sure the loser follows the peace conditions. The Thalmor are guaranteed free access in Imperial territories (IIRC) and having such an amount of enemies inside your borders means you have to play along with them, especially as, like a Thalmor agent puts it, the Dominion could wipe out the Empire if they just wanted to.

Tullius has no other choice but to play along with his new masters and heroic rebellions will have to wait until the Empire regains its power.

I made her suffer and beg for mercy before I lopped her head off.


@Topic
I personally believe Tullius is the best chance we got against the Thalmor in Skyrim. He doesn't give a **** and shakes their hand just cause the Emperor asks him to and that too he does with his other hand up theirs.

I agree with Uriel_Septim_VII above. I think the General conveys his opinion of the relationship between the Empire and Thalmor clearly at the end of the Civil War questline, if you align with the Legion.

The terms of the WGC was the banning of Talos, southern Hammerfell to be given to Dominion, and allowing the Thalmor access to the Empire's lands.

Tullius doesn't like the Thalmor, at the of the Legion questline he says that peace isn't going to last between the Empire and the Dominion and I've heard if you play the Stormcloak ending before you kill him he states that the Stormcloaks are playing right into the Thalmor's hands. The reason why the Thalmor was allowed in council was due WGC. The Thalmor knows that the Empire gave Skyrim the right to worship Talos openly before and they can't allow that again. Tullius probably didn't want to give the Thalmor an excuse to start a war that wasn't in the Empire's favor

Tullius must side with the Thalmor... He doesn't want to give the Thalmor an excuse to star a new war, which the Empire is not prepared to.
Spoiler If u side with the Empire, after the battle of Windhelm he says that the only thing that perplexes him is the alliance with Thalmor

Tullius doesn't like the Thalmor, he just does it for necessity, watch from about 5:00 until Tullius is killed.

http://www.youtube.com/watch?v=gT3je0hgbJs

Spoilers obviously.

he currently has no backbone like the rest of the empire.

no strong leadership......

he knows this and is waiting for the emperor to show that he has a pair. or someone to rise that cant tell the thalmoor where tostick it.

Tullius is a military. They have to follow orders even if they have a different mind/opinion on the subject.

+1

If I ever manage a character that sides with the empire, I'll have to keep a permanent clothespin on my nose. All the politicians and milk drinkers around just stink.

This.