See the recent editorial in The New York Times about the 'slow demise of capital punishment'. 'Slow' is a very subjective notion, and from the perspective of the United States the process may appear to be taking a long time. That's partly because the United States once appeared to be a pioneer on the subject, in the late 1960 and early 1970s, when the practice virtually stopped and the Supreme Court came painfully close to judicial abolition. Later this all got reversed for a couple of dark decades, but at a time when the rest of the world seemed to keep moving forward, and rapidly, on the subject.
Thanks to Sir Nigel Rodley.