between a rock and a hard place

I met this idiom by chance while reading the article. It discussed the fact that Chinese government devalued the yuan (phá giá nhân dân tệ).

So what does this idiom mean?
It expresses a very difficult position or a situation that facing a hard decision.
Between two equally difficult or unacceptable choices.
Examples:

1. I couldn't make up my mind. I was caught between a rock and a hard place. He had a dilemma on his hands.
2. He was clearly between the devil and the deep blue sea. 
3. I’m between a rock and a hard place. I don’t know what to do 
4. Trying to please both my boss and his supervisor puts me between a rock and a hard place.

Thành ngữ này gần nghĩa với:

between the devil and the deep blue sea

http://idioms.thefreedictionary.com/between+a+rock+and+a+hard+place