A country as vast as China...,A country应该是作为主语吧?

A country as vast as China...,A country应该是作为主语吧?
A country as vast as China with so long-lasting a civilization has a complex
social and visual history,within which pottery and porcelain play a major
role.
翻译成：中国历史悠久,地大物博,这样的国家都具有复杂的社会历史和视觉历史,其中陶瓷就扮演了重要的角色.
结构是不是这样的,
A country （as vast as China）（ with so long-lasting a civilization） has a complex social and visual history,[ within which pottery and porcelain play a major role.]
A country 是主语,has是谓语,a complex social and visual history是宾语
可是这样的话,那个with so long-lasting a civilization里面的a好奇怪~