那个大虾帮忙翻一下这个句子~之中OVER是怎么个用法?还有就是FROM WHERe是个什么意思,谢

那个大虾帮忙翻一下这个句子~之中OVER是怎么个用法?还有就是FROM WHERe是个什么意思,谢
But confusion broke out on Monday among the allies in Europe over who exactly would carry the military operation forward once the United States stepped back,and from where.

我理解是,over指的是“对于”,它其实是跟在“confusion”后面的,这个疑惑（confusion）是对于（over）后面的一整句话“who exactly would carry the military operation forward once the United States stepped back,and from where”的疑惑
而“from where”是跟着“who”,表达的是因为老美退缩了,所以他们疑惑了,疑惑神马呢?疑惑谁,从哪里,出兵,就酱