Standing around praying or sharing hash tags about terrorist attacks will not stop the next terrorist attack. Short term, killing someone carrying a bomb is the only way to stop them from killing people.
Long term, engagement to fight the extreme views of fundamentalist Islam can change things. But this is a long battle of ideas because 3/4 of young Muslims in the West support incompatible ideas like "freedom of speech should be denied if Muslims don't like it" and "make things illegal that are forbidden by Islam". Making things worse are the 1/4 of young Muslims who support violence/Jihad to spread Islam and Shariah law according to Pew polls and others.
When a quarter of young Muslims in the West say they have the right to kill people for not being Muslim and half their peers would not turn them in, you cannot blame the West for its views but only Islam's ideology that fosters such views.
They are taught that infidels are firewood for hell, that it is better to be dead than an unbeliever, that anyone disagreeing with their beliefs has insulted the divine and attacked them personally and can be killed. You can't stop Islamic violence without confronting Islam's violent tenets and challenging them.
The bad part right now is that so many liberal secular people say "Islam is a religion of peace", what they wish it was, that they do not try to change the views of Muslims - including those whose views give them permission to kill critics.
Things will not change until the world collectively stops saying what it wishes was true and admits that both the Koran and Mohamed's examples are mostly violent, and then work to foster the peaceful factions of Islam while no longer tolerating much less acquiescing to the violent ones.