If hydrogen peroxide--which is good possibility, as high-grade explosives hard to get in Western countries--it would imply training, as unstable chemicals need careful handling, writes Peter Bergen.
원문출처 : http://www.cnn.com/2017/05/23/opinions/manchester-attack-bergen/index.html
원문출처 : http://www.cnn.com/2017/05/23/opinions/manchester-attack-bergen/index.html