句子语法求分析！！！！！

gabriellenyc

In the postwar decades, when major American industries emerged from
World War II as oligopolies with limited competition and large, expanding markets at home and abroad, their profits and
future prospects allowed them to offer employees defined-benefit pension plans,

这段话中 american industries emerged from ww2 as oligopolies with limited competition, emerged 是和后面的as相关联表示“industies emerged as oligopolies" 的还是“as....”表示一个原因状语从句？
如果是表示原因状语从句，是不是缺少个谓语？也就是as oligopolies are with limited competition......
thanks in advance

bejamin1111

这句话的意思是：在战后的几十年里，主要的美国行业从二战里作为寡头浮出水面，这些垄断行业面对极少的竞争，并且在国内外不断扩张市场，他们的利润及前景使得他们能够为雇员提供养老金固定收益计划；
这里as表示作为，意思是having the function or character of ，with引导的modifier修饰oligopolies