Didn't the Brits try that with the
Indians?
The US is re-learning lessons that the British had to learn the hard way. As global hegemon, you can only project power by military force so far, before you can no longer keep killing people as fast as the survivors can start hating you.
There was a time when a British person could wander through Kabul, secure in the knowledge that nobody would dare assault him, because to do so would invite a massively disproportionate response.
America never reached that point in Kabul, but they were working on it, and they have reached that point in much of the developing world. But it's an unstable way to secure your citizens, as it's got a tendency to suddenly flip from 'these people are untouchable' to 'we're probably getting shot anyway, so let's take as many of these bastards down as we can'. As the British discovered repeatedly, and as the Americans are still struggling to comprehend.
Imposing your ideals and way of life on others by force can be very effective, for a surprisingly long time; But ultimately it always ends in violence. You can force people to fear you, but you cannot force people to respect you.
