Also important were military chiefs, who had control over the frontier regions.

The same applies to the frontier regions, which are not always rich and able to help themselves.

Many notes describe the natural resources and potential for settlement of frontier regions.

As a mountainous frontier region, it was difficult to dominate.

For example, China had little success populating the frontier regions.

When it comes to the frontier regions, though, you cover yourself with modesty.

But in this eastern frontier region at that time, the prospect of a Soviet invasion was never far from anyone's mind.

How much human suffering passed in the frontier region without public notice by any government remained unknown.

The frontier regions will therefore come under particular pressure when the freedoms in question are introduced.

Turmoils in the frontier regions of China began to spread.