Economic historians are also increasingly questioning whether state support for manufacturing did, in fact, play as decisive role in the economic development of East Asia and the West as is commonly assumed.
请问亲爱的老师，在这个句子中，第二个as引导的是定语从句是吗？role前为何没加冠词a呢？
1 这是as+形容词+名词 + as比较分句结构。as比较分句省略了形式主语it和外置的that从句。补全比较分句则为：... as it is commonly assumed that it will do. （第一个it为形式主语，第二个it指代state support for manufacturing。）
2 有些传统语法书觉得当先行词被as+形容词修饰时，定语从句由关系代词as，而不是that。所以有人或许会依据传统语法把本句中的as分句剖析为定语从句。但依据本句的语义，把as分句剖析为定语从句显然是不对的。由于根据定语从句剖析，as指代the decisive role，则定语从句的语义为the decisive role is commonly assumed，这个定语从句的语义是不完整的。意为assumed的逻辑宾语并非名词the decisive role，而是state support for manufacturing plays a decisive role。换句话说，assumed的主语应该是一个从句，而不是一个名词词组。所以本句中的as分句用定语从句是讲解不通的，只能根据as引导比较分句做讲解。
3 role前应该用冠词a。
