buffer zone; buffer area
A neutral area between two opposing forces or regions, often used in geopolitics, ecology, or computing.
A buffer zone was established between the two countries.
This nature reserve functions as a buffer area between the developed zone and the primeval forest.
緩衝地帯 is a more common synonym for 'buffer zone', while 緩衝領域 is slightly more formal and technical, often used in academic or policy contexts.
Compound of 緩衝 (buffer, shock absorption) and 領域 (area, territory). The term is a modern technical coinage, likely influenced by English 'buffer zone'.