This really shouldn't be a thing....

[Mattzey]

Don't put yourself into position to border your more powerful allies. It has been true in EU 4 since day 1 (although the degree of wreckage it does has varied some) and remains so. As soon as you share a border with a bigger blob, especially a militaristic one, your land becomes "their land". At least with the current rules if you can get trust up high enough before you collide you have a chance to avoid it (although you'll still see the ai do stuff like peace out early and drop your trust below the limit).

But he didnt share a border until the ally he helped in the war gave HIM the province so they bordered eachother which then made him go hostile and break the allaicne, yep totally his fault for choosing to border austria.

 

[Xara]

Unless it's changed recently, you don't get unlawful territory when you're allied to the emperor. So, the alliance had to break before the unlawful territory modifier could happen.

You don't get the demand but there is still a penalty for unlawful penalty.

Try it yourself : Play Brandenburg until you can just barely ally the Emperor (Austria). Then fully annex Pommerania. Those 5 provinces will immediately cause them to drop your alliance due to -20 x 5 relations.

You also get the -prestige (and legitimacy?) per province so long as they are uncored, whether or not you are allied to the Emp or even if you *are* the Emp.

 

[brifbates]

But he didnt share a border until the ally he helped in the war gave HIM the province so they bordered eachother which then made him go hostile and break the allaicne, yep totally his fault for choosing to border austria.

He had the option to not occupy that province during the war, not place a claim on it before the war and/or to not set it as a province of interest. All of these would keep the ai from granting it to him in the peace deal. There's also the option to separate peace out of the war rather than getting stuck with land that is liable to harm your long-term plans...

 

[Gratak]

He had the option to not occupy that province during the war, not place a claim on it before the war and/or to not set it as a province of interest. All of these would keep the ai from granting it to him in the peace deal. There's also the option to separate peace out of the war rather than getting stuck with land that is liable to harm your long-term plans...

He is playing palatinate. Whether he comes to Austria or Austria comes to him doesn't matter. Eventually they would border each other anyway. And as mentioned multiple times here already, the "-17" due to austria wanting the province could not be the sole reason for an alliance break...

 

[Cathal341]

He had the option to not occupy that province during the war, not place a claim on it before the war and/or to not set it as a province of interest. All of these would keep the ai from granting it to him in the peace deal. There's also the option to separate peace out of the war rather than getting stuck with land that is liable to harm your long-term plans...

I did actually want the province(My AE was low and my short term goal was to connect up my lands) what I did not expect was Austria to back stab me and Alliance break over it.