Why was west berlin described as a "bone in the throat" of the soviet union?

After the congress of vienna europe

Which action by the us war department angered chief red cloud to the point that he refused to sign the treaty of fort laramie ? a) the killing of buffalo by the united states troops b) the appointment of troops to the powder river basin c) the burning of parts of the powder river basin d) the murder of chief red cloud’s wife

How many battles in wwii were fought on u. s. soil? a. 0 b. 1 c. 2 d. 3