Reasons for the recent rise in long-term unemployment
I would "advise" to wait... a few more years! From the figure you provided, there is a perhaps slow but visible rising trend (with business-cycles-like "seasonality") for both the long-term and the mid-term unemployment rate, a fairly stable trend in terms of steepness over 60 years. The sudden peak of long term unemployment in 2009 is impressive but it also fell sharply in the next three years. To me, it appears critical to know the unemployment rates for the next four-five years, in order to decide whether we have a structural break with the historical rising trend becoming more steep, or just a few-years-incident due to the crisis.