oblige
[+ object] : to force or require (someone or something) to do something because of a law or rule or because it is necessary

• The law obliges the government to release certain documents to the public.

• Her job obliges her to work overtime and on weekends.

常用作被动语态：

The government is obliged [=required, obligated] by law to release certain documents to the public.

主动语态时，不定式为宾补。在被动句中，不定式是主补。不是目的状语。

I felt obliged to ask them to dinner.

本句中过去分词短语作表语。其中不定式不是分句成分，而是过去分词obliged的补足语。