| I think that the population of a country could put up a major fight against an occupying force (maybe not to so much of an extent during the initial invasion, but definitely after occupation or at least after a period of time after enemy troops entering the country). We've seen this many times in history, and I don't live in the US, but I know that in NZ there's allot of places for locals to hide, group, stock supplys, whatever, and guerilla warfare can overwhelm, or at the very least be a major thorn in the side of, a far larger military fighting force. In a country in the US, where far more superior weapons can be bought far easier than most other countries, it'd be even more so.
Imagine what 10 average guys with even just sub-par hunting rifles, perhaps some low grade pistols, and a decent knowledge of basic combat and some explosives could do.
There's no doubt that you could wreak havoc, to some extent at least, but the only question is; how many people are truly willing to put their lives on the line?
A sufficiently determined and motivated civilian population could definitely be a major advantage to a defending country.
The police? I don't know- there's no history I am aware of where police have made a notable difference. I'm sure they have, but in the majority of cases police aren't going to be targeting enemy forces- they'll either be policing civilians or just doing whatever the hell else everyone else is doing.
It all depends, of course, on the scale of the invasion. How many land forces are there? How well equipped are they, and do they have air support? Is naval, or even missile, based combat going to play a role? Are they deep into the country and cities, or being held at a distance by defending forces? Depending on the stage, scale, and development of the invasion, the civilians and police could play extremely different roles. |