I believe that the Government's general aim is to whittle away the Welfare State. [VERB PREP. noun]

我认为政府总的目的是要削弱福利国家体制。

Their approach is to whittle away at the evidence to show reasonable doubt. [VERB PREP. + at]

他们的做法是要削弱证据的说服力以提出合理的质疑。