It was up to the US to take the initiative in repairing relations.

在修复关系方面应由美国采取主动。

We are the only power willing to take the initiative in the long struggle to end the war.

在旨在结束战争的长期斗争中，我们是惟一愿意首先采取行动的国家。

Why don't you take the initiative?

你为什么不采取主动呢？

It is up to you to take the initiative.

你要占据主动。

Take the initiative. You'll be rewarded for it.

只有采取主动，你定会有所收获。