15. 定义难题仍然是一个长期存在的问题，因为旨在防止和打击暴力极端主义的政策仍在发展中，而对这些政策旨在解决的现象没有明确的概念。本报告所述的
15. The definitional conundrum remains a persistent problem, as policies aimed at preventing and countering violent extremism continue to develop without a clear notion of the phenomenon they are aimed at addressing. Many of the issues addressed in the present 21 A/70/674, para. 4.