Silly boy, you don't understand. The government doesn't have to go after 300,000,000+ people in the country. Many will be on the side of the government. Many won't want to get involved. I know it is hard for you to understand because you are a paranoid idiot, but people who think like you are vanishingly rare.
Oh, I know what you are thinking "But, I saw V.....", but that was a movie based on a graphic novel, not reality. In reality, V would have been dead in a few days at most.
BTW, the only reason it "took the U.S. Government a trillion dollars and half a million soldiers to destroy the roughly 20,000 members of Al-Qaeda in Iraq and Afghanistan" was because of Iraq, embedded reporters, and an attempt to be nice because the war was televised. I know it is hard for someone as simple as you to understand, but if the U.S. had acted like it had in WWI and WWII, before televised war, the U.S. armed forces would have carpet bombed Iraq and Afghanistan. We would have dropped thousands of large, cheap, conventional bombs and daisy cutters to kill the enemy soldiers, then used bunker busters on the REMFs. They would have leveled cities and towns. They would have rounded up people in remote locations and put them in camps. They would have mined the passes they didn't want used. They would have dropped bunker busters and cluster bombs. They would have a much higher civilian casualty rate and no one would have known or cared. And, things would have been a lot different.