We could fight a guerilla war succesfully IMO. Maybe not win outright, but at least drag it out (ie Vietnam)
Guerrilla war (insurgencies) aren't won by killing all of your enemy. We're a long way from mass warfare, e.g. Genghis Khan or George Patton.
Insurgencies are won by making the battle too expensive for your opposition to maintain the operation. It is FAR more expensive to guard 1,000 points, not knowing which will be hit, than it is to pick one and hit it. (Look at either the Transportation Security Administration, or Border Patrol, for an valid example of this in modern day real life - or even the "show up and write a report" disposition of all modern metropolitan police forces.
Once upon a time, not so long ago, 19 bad guys (
http://en.wikipedia.org/wiki/September_11_attacks) caused a wave of counter-events that have cost this country trillions of dollars.
A successful insurgency on home soil doesn't even have to involve bloodshed to be highly effective (although bloodshed increases the shock value; it is a sword without a hilt; dangerous to wield for both aggressor and defender, from a political cost standpoint). Well educated aggressors attacking infrastructure can carry exceptionally high costs from a political and economic standpoint. Oil / natural gas lines, electrical distribution, rail transportation, telecommunications.. all extremely vulnerable and ran through endless miles of unoccupied countryside.
Turn-cloak insurgents also can carry an extremely high cost even when they are located in relatively modest levels of security - E.g. Snowden, Manning.
Ultimately if you want to get a modern government to fail, you have to expense it in to a downward spiral until the government itself becomes too cumbersome to maintain. This holds true even if warfare is the method of causing the collapse. Warfare is expensive and will bankrupt the lessor power, eventually causing defeat.
Then you can have a non-violent victory once the government is bankrupt and form one which is more sensible. (
http://en.wikipedia.org/wiki/Civil_Disobedience_(Thoreau)). Over a century and a half ago, Thoreau postulated that if a sufficient amount of people stopped paying taxes it would force the government to a halt, bring all of the issues to a head, and force a change of power.
The alternative to that is to force the Government to expense itself to death - as you won't find enough traction in the anti-tax movement on a country this size to see his vision to fruition. The other end of the equation is more possible - force the government to spend far more money than they bring in on taxes until it collapses under it's own weight.
They are ALREADY doing that without any push from an insurgency of any sort. Imagine how rapidly it would decline if one were to begin in earnest?
Nay.. the next Revolution doesn't have to be fought with bullets, and smart bombs, and tanks, and jet fighters won't even factor in. The next revolution will begin when the government collapses under it's own weight. The next government that rises from the ashes, depends on who (or what) is in what positions of power when this happens. There will be a very large void, and it will be very chaotic, and blood will be shed by honest and evil, but something new will rise.
For better or worse? We can only wait and see.