范奥斯塔延说，他对这些袭击者的看法可以用美国外交政策研究所（FPRI）高级研究员克林特•沃茨（ClintWatts）博文中的一句话总结。
Mr Van Ostaeyen says his feelings on the attackers are summed up in a blogpost by Clint Watts , senior fellow at the Foreign Policy Research Institute .
外交政策研究所