buffer state
buffer country

Their marriage served as an alliance between the Ottomans and this buffer state.

I took my seat beside him, while the lady, a useful buffer state, was squeezed in between the two men of wrath at the back.

They had therefore cultivated Tibet as a buffer state.

The main American objection at the time was that the buffer state denied its inhabitants the right of self-determination.

In 1814, after the fall of the empire, a buffer state was created, with Vesoul as capital.

Indirect rule was also established on protectorates and buffer states.

Half a dozen little buffer states would have kept them at peace.

She had lost the buffer states which protected her and she was vulnerable to land attack.

Presumably, it will then be a buffer state against Iran.

The British wanted the Indians to form a buffer state between the two countries.