请教一道 关于倒装的题

2012success

Affording strategic proximity to the Strait of Gibraltar, Morocco was also of interest to the French throughout the first half of the twentieth century because they assumed that if they did not hold it, their grip on Algeria was always insecure.
    

B. Without it their grip on Algeria would never be secure
C. their grip on Algeria was not ever secure if they did not hold it.
D. without that, they could never be secure about their grip on Algeria
E. never would their grip on Algeria be secure if they did not hold it. 
 

为什么不可以选E呢？是不是因为否定性词或短语引起的倒装必须放在句首呢？

ranning

这道题考句子简洁，我想这样理解最好