N-COUNT
（某国的）后院（指本土或该国意欲施加影响的邻近地区）
If you refer to a country's own backyard, you are referring to its own territory or to somewhere that is very close and where that country wants to influence events.
例句
Economics will not stop Europe's politicians complaining when jobs are lost in their own backyard...
当本国人口在失业时，经济情况是无法让欧洲的政治家停止抱怨的。
Cuba is the largest island in the Caribbean, an area that the United States has long regarded as its own backyard.
古巴是加勒比地区最大的岛屿，美国长期以来一直把它看作自己的后院。