Civilian resistance as a national defence: non-violent action against aggression

The text that follows is taken from the back cover:

After Russia's brutal invasion of Czechoslovakia it became clear that many civilian activities (including radio and press) had been successfully, if spontaneously, deployed to resist the invader.

We now have to ask ourselves whether a nation can defend itself effectively against armed attack by non-violent means. Can civil disobedience, strikes, boycotts, underground newspapers, and the whole armoury of passive resistance be expanded and co-ordinated into a strategy of national defence, with patriotic government running in parallel with enemy or puppet authority? Many experts believe they can.