Some Americans want to go further and undermine him(Gorbachev), even to encourage a breakup of the Soviet Union. That would only play into the hands of reactionaries, not help the reformers.
有些美国人要进一步削弱他（戈尔巴乔夫），甚至鼓励苏联解体。那仅能予以反动派可乘之机，而无助于改革派。
Beware of the fifth column. They often infiltrate into key positions and seek to undermine the body politic from within.
要提防隐蔽的敌人，他们经常渗透到关键岗位企图从内部破坏国家政体。
An investigation carried out ostensibly to uncover subversive activities but actually used to harass and undermine those with differing views.
政治迫害表面上是开展揭露颠覆的活动，但实际上用于扰乱和削弱持不同看法的人的调查
