Western countries have hardly been immune. In fact the US has hardly been immune.

Some methods:

Media influence - 'pundits' and reporters either funded with Washington money and paid to produce talking points on cue, or pressured by management not to cover certain stories.

Indirect and false front campaigning, as per Mr Ganley.

Funded support for expedient movements and political action groups.

Think tanks - q.v. pundits.

Infiltration of activist groups for reporting and direct influence

Direct pressure on politicians through blackmail or threats

Agent provocateur operations to discredit activist groups

Assassination and other covert ops

False flag domestic terrorism

Coups and attempted coups

Vote fixing

You don't need to suggest a conspiracy - the conspiracy is obvious and all of these operations are a well-documented part of the historical record.

It's nice to pretend we're living in a happy shiny democracy, but really - not so much.