Military Access - diplomacy

[Tamur]

Has anyone been able to negotiate for military access (being able to march your armies through an ally's provinces to attack elsewhere)?

I'm currently playing as the Brutii, have an alliance with the Macedonians that's been solid for twenty years (268-248, fourty turns). I've done everything -- asked for military access with a "blank check", offered mutual military access, asked for military access while offering to attack the Greeks who they are at war with, asked for military access while offering to attack the Greeks AND give them Sparta, etc etc.

To every offer, they respond with, "From your past deeds we'd have to be slobering idiots to let you march over our lands." But, as I said, the alliance has been solid with no breaks on either side.

??? This is the part of diplomacy I was looking the most forward to -- being able to enter allied territory and help them against attackers.