你能解释一下这项政策背后的逻辑吗？

Can you explain the logic ___behind this policy?

他慷慨背后的真实动机仍然未知。

The real motive ___behind his generosity remains unknown.

他们突然合作背后肯定有隐藏的议程。

There must be some hidden agenda ___behind their sudden cooperation.