The thin end of the wedge is dangerous.

楔的细端是危险的。

This demand is only the thin end of the wedge-soon the will want more and more.

这一要求还是一个开始—他们很快就会提出越来越多的要求。

It's the thin end of the wedge - perhaps in your past someone left saying it was temporary, but didn't come back.

这是分手的前奏-也许曾经有过某个人说离开是暂时但是却没有回来。

Thereal reason that Japan is so hell-bent on continuing its whaling isbecause it fears that a ban would be the thin end of the wedge.

日本如此决意继续进行捕鲸活动的真实原因是，它害怕一纸禁令将是冰山一角。

This is perhaps a trivial example, but analysis of the type I have just described can be the thin end of the wedge in penetrating a cryptosystem.

这或许只是一个简单的示例，但是此类分析可能是渗透密码系统的一个开端。