VIOLENCE JUSTIFIED?

It is often argued that it is understandable that Muslims are reacting violently to perceived injustice. It is understandable that British Muslims enraged by their country's foreign policies react by bombing civilians and that Muslims angered by Danish newspaper cartoons seek to blow up German civilians.

Would it not also be understandable, if such atrocities and near misses continue, that non-Muslims also become enraged and react violently? I mean, this violence justification thing must work both ways.