This post keys off the comments to this post, so if you don't go and read those first, this post is going to be a waste of time for you. Or maybe not. As a prefatory note: I'm not participating in the comments since Thrasher is an ignorant idiot or a troll and Craig Nulan (subrealism) is coming from some weird POV that I'm not fully sure I understand. He also doesn't take me seriously, which makes it extra difficult to engage with him.
As much as it forms a staple of many technothrillers and other SF novels, I don't see the USSR or the PRC actually trying to bust our cities and kill our people. At the risk of sounding paranoid, I think they're playing a longer game. The Russians under Putin are still playing the memetic warfare game, trying to get the average American to lose faith in the central republican idea of American constitutional government and the moral underpinnings thereof. The allies/useful idiots of the Russians can be found in the New Left wing of the Democratic Party, who are beavering away in academia, the government bureaucracy, and the news/entertainment industry at their task of expanding an increasingly bureaucratic Federal government at the expense of the states and the people, corrupting the information stream, and undermining the philosophical/religious tradition of the West that culminated in the revolutionary document that is our Constitution. The allies/useful idiots of the Chinese are the "centrists" of the Democratic Leadership Council, the triangulators associated with Bill (and now Hillary) Clinton. Their aim is to use Washington as the armature of a corrupt, crony capitalist state that will have the benefits of capitalism harvested for the elites at the expense of the proletariat and bourgeoisie. It is the subconscious perception of their aims that drives the Tea Party and the libertarian wing of the Republican party, while the insiders and RINOs seek a compromise that slows but does not turn back the subversion of the cultural-political system.
Either way, the future if the Democrats somehow manage to retain power is going to be a lot like the present, only worse: those favored by Washington will become (or remain) rich and powerful, while the official enemies will be impoverished and/or imprisoned by a judicial system that no one man or corporation can afford to fight. The vast middle class will become a small band of government workers and middle-echelon salarymen, and the rest of what was the bourgeoisie will collapse into the unemployed/underemployed proletariat. And ethnic minorities will be hardest hit, with a thin veneer of ruling class blacks and Latinos on display to perpetuate the lie of equal opportunity.
I don't see the military taking up arms to prevent this, unless the next few elections are marred by significant and successful vote fraud that keeps the Democrats in power and the desperate elements of the conservative movement resort to secession and warfare. I don't see Petraeus or anyone like him becoming our Franco.