The pages of history are littered with examples of military conflicts, small armies form allegiences with larger, more powerful ones, to impose their will upon others. The primary objective of a military force is precisely that.
The civilian populations which suffer the consequences of the invasions are usually prone to form their own pockets of Resistance to the new rule of law which is forced upon them. To the more powerful force, these are 'terrorists', a carefully chosen word to describe what the resister will see as an honourable struggle to return to normality, a 'freedom fighter'. As the issue is determined by force of arms, the mightier force dictates how the population should receive them and then the politicians take over the role of the military. I believe that to be a fair representation of what generally happens throughout the world, the general population is unable to accept all the new changes to their culture and thereafter are subjected to the whim of the politicians who constantly re-assure them that their lot will be better for them, it never is of course, things are never the 'better' only 'different'. Superior weaponry is the key to a successful military campaign, the defending force has little chance of surviving unless it can secure the help of other forces likewise threatened. The American history is a fine example of all the fore-going comments, a nation created out of the destruction and decimation of an entire culture of truly wonderful folk who still suffer from the injustices of invasion.