There are 2,300,000 Active and Reserve in the US Military. For the sake of argument, let's assume all troops across the world are brought home for this exercise. There are 860,000 Police officers. This includes detectives, Street cops, transit police, and even fish and game wardens. That's a total of 3,160,000 boots on the ground. Let's have these guys work 12 on/ 12 off and then we reduce that to 1,580,000 for active boots on the ground.
There are 6,400,000 people in Massachusetts alone! Boston itself, not including the surrounding cities of Lynn, Somerville, Braintree, Framingham, Quincy, etc is 90 square miles. This is all highly populated urban environment. How many thousands of intersections are there that will need checkpoints?
What our military is learning from Afghanistan is that the only way to control a population is with boots on the ground. Fancy robot flying machines act as force multipliers, along with tanks and C3, so on and so forth. But it is the soldier that makes it happen.
There are 167,000 total troops in Afghanistan right now, and the country is anything but pacified and controlled. Ant the country is only 250,000 square miles. The population is concentrated in several cities and then sparsely populated across the rest of the country. America is ~3.8M square miles, with many, many major cities that sprawl into each other.
Just scaling up the area of the countries, the US is ~15x bigger, so that needs 2.5M troops. We have 10x as many people, so that means 1.67M troops.
There simply are not enough boots to go around and lock down the whole country at once. The average Afghani is smart enough to know not to screw around with people with machine guns. The average resident of Roxbury, or Detroit or LA, thinks they have "rights" even under Martial Law. So it will take more troops to keep order here in America than in Afghanistan. Riots. Food hoarding that becomes food rationing. Gas, diesel, and home heating oil shortages. Brownouts and forced electrical grid shutdowns are all going to be part of it.
I wonder how long before people get sick of it and really cause trouble?