I'm not sure if you could achieve full-on dystopia in less than 15 years. To me, difference between a mere post-collapse scenario and a dystopia is that the latter is a society that's more or less functional but horrifyingly oppressive and highly fortified against any uprising. For an example of a universe with both, look at Star Trek. The era of Sanctuary Districts for the poor and "undesirables" of society and needing a license to use the internet would be dystopian; the years between World War III and First Contact where nation-states were gone and various "factions" took their place would be a post-collapse scenario. For a real life examples, the Great Depression before the New Deal could be considered a post-collapse scenario; China is becoming increasingly more dystopian (if all news about them is to be believed).
I think the latest POD you could have to make things dystopian all over by now is the September 11th attacks being worse. Say that the plane that hit the Pentagon hits the Capitol building instead. Or more of the hijackings succeed and one of them hits a major power plant and disables the grid for much of the country. For America, it seems like the prophecies that supposedly said the world would end at the end of the second millennium came true, but a few years late. Emboldened, al-Qaeda attack several other targets in North America and Western Europe. To settle the chaos down and restore order, several governments declare martial law. Culturally, the mood becomes one of paranoia and clinging to extreme nationalism for comfort.
Through technology, by 2019 much of the Western world is a full-on surveillance state, with any dissent treated as "treason" and therefore punished accordingly.