The use of 'force' is not always necessary
eg: The UK Glorious Revolution of 1689
Basically the British political class were fed up of James II, so
although William came over with an army, he had been invited, and the
army was not really necessary. William's wife Mary was the next in
line for the throne as it was widely believed that her much younger
brother had been smuggled in to the birth in a bed pan.
I would not call the American Revolution really a 'revolution'
- it was a colonial revolt, the UK Government was unchanged, and the
USA suddenly acquired a totally new Government.
There is also the difference between a 'revolution' and a coup d'etat,
which is essentially a military takeover.
You would probably be wise to consider the use of the phrase 'popular
revolution', where a large proportion of the population turn on the
existing government and kick it out.
I'm not sure about the French Revolution, but what happened in the
Russian 1917 and the Iranian 1979 revolutions was that the middle
class, students etc and peasants got hacked off with their rulers. In
both cases rather unpleasant extremists managed to grab control. The
similarities have always struck me as interesting.
The Chinese Revolution was not so much a 'revolution' as two factions
scrapping when there was not much government.
Their 'Cultural Revolution' was no such thing, it was a cull of intellectuals.
In Eastern Europe we have seen a number of 'revolutions', but
generally they look more like the rulers losing heart in the face of
Just to muddy the waters there was the 'Industrial Revolution' ...
Words can sometimes be a bit tricky, especially describing political history.