I have to step into the breach when my boss was not in the company.

当老板不在公司时，我不得不充当临时代理人。

This leaves central Banks having to step into the breach, as they did last December when interbank rates exploded.

这使得央行不得充当“补位”的角色，这正如去年12月银行拆现问题爆发时一样。

And even if China is shifting out of us Treasuries, it would not necessarily cause trouble in the market as long as other buyers step into the breach.

况且，就算中国对美国国债避而远之，只要其它买家能够补上缺口，就未必会给市场造成麻烦。

If the U. S. walks away from these principles, other countries such as Russia will step into the breach and trample on the very rules that keep Americans safe.

如果美国放弃这些原则，像俄罗斯这样的国家就会违反和践踏规则，而正是这些规则保护了美国人的安全。