Although I am also a chinese ,I think I am supposed to be able to answer your question.As the Maidhc said,it's a little bit impolite asking like "I want". Now the structure would be more clear,if I divide the whole sentence into several structures.But it is precisely that,asumption (which must now be discarded) ,so that,we can think strategically about our new relationship to the environment. The chinese meaning of the sentence would be "现在必须抛弃这种假设，以便我们可以从战略上思考（我们）与环境之间的新关系。so that 前面我认为实际成分只有一个assumption，没有主谓结构。