Ambassador Stephen W. Bosworth, former special envoy to North Korea, said tonight that Kim Jong Il’s death is “a shock in some ways’’ but not a huge surprise. Bosworth served as the US special representative to North Korea from February 2009 until two months ago when Ambassador Glyn Davies was named his successor. Bosworth, dean of the Fletcher School of Law and Diplomacy at Tufts University, said an “anxious and sensitive time’’ may be ahead in North Korea.