"After the war, contact was established and he has proven his worth as an asset.The so-called Markarth Incident was particularly valuable from the point of view of our strategic goals in Skyrim, although it resulted in Ulfric becoming generally uncooperative to direct contact."
The wording is clear. Ulfric was an asset who was in contact with the Thalmor and advancing their strategic goals. Ulfric only bailed after the Markarth Incident.
So he did it as part of their plans, as a conscious asset of theirs. To get any other meaning out of those words requires twisting them all out of shape.
But hey, it makes your boy Ulfric look bad, so, not relevant!
Pull the other one; its got bells on.
Dude, Talos worship was officially banned thirty years ago. Why did it only become a killing issue now? Its not like the Thalmor Justicars were in Skyrim thirty years ago! Talk to the blacksmith in Riverwood; that [censored] only started after the Stormcloaks rose up.
So basically, unrest only exists as long as Ulfric is pushing the issue. Sounds like the best thing he could for Skyrim is tie an anvil to his feet and jump off a bridge.
PS: I might also point out that Ralof, the Stormcloak guy who rescues you in the prologue, eventually ends up deserting from the Stormcloaks. Why? Because he finally wises up that Ulfric is a power-hungry douchenozzle who isn't sincere about the cause, he's only using it to gain followers for his own power. The man's own bodyguards start ditching him.
Hell, even his lieutenant, General Savage Kills-Them-All (or whatever his name actually was) ends up being all heartbroken after the Stormcloak campaign finishes with a victory, aghast at how much of Skyrim they destroyed while trying to save it.
What more does the game have to do, have Ulfric eat a baby?