《旧唐书·列传·卷一百二十二》
几年时间，几乎危及社稷安全，而牛僧孺按一定准则求进退，为议论者称道。
数年之间，几危宗社，而僧孺进退以道，议者称之。
In just a few years, he almost endangered the safety of the country, while Niu Sengru asked for promotion and demotion according to certain rules, which was praised by the commentators.
<s>[INST] Identify the key themes in this Classical Chinese text and explain them in English: 数年之间，几危宗社，而僧孺进退以道，议者称之。 [/INST] In just a few years, he almost endangered the safety of the country, while Niu Sengru asked for promotion and demotion according to certain rules, which was praised by the commentators.</s>
Identify the key themes in this Classical Chinese text and explain them in English: 数年之间，几危宗社，而僧孺进退以道，议者称之。
user
In just a few years, he almost endangered the safety of the country, while Niu Sengru asked for promotion and demotion according to certain rules, which was praised by the commentators.
assistant