What more can countries do to stop these acts of terrorism?

Stop electing liberal globalist utupoian control freaks. Start to mock the mainstream media and demand education return to teaching and not liberal indoctrination. Teach the young people the art of critical thinking, throw facebook and twitter in the trash and return to individualism and personal liberty.

Stop the war on terror and work with the majority Muslim population against the extremist minority.

Cut financial ties with countries that fund the building of mosques, like Saudi Arabia.
Send to court those who write messages supporting jihad or sharia. Ban them from the country forever. Do the same with all those who own sites where they are glorified.
Set an immigration ban on countries where there is an evidence of jihadists being trained

There are only two answers. Pogrom or cooperation. I prefer cooperation. I really do.
People need to learn that Mohammed was the Prophet of Mecca as well as the warlord of Medina, and the five pillars of Islam were not conceived in Medina , any more than a Christian father is supposed to bash his daughter's head in with rocks if she is not a virgin on her wedding day. We as westerners see an antiquated, draconian, patriarchal, and misogynist dogma, but it doesn't have to be like this. We either compromise or kill. Simple as that.....or 'complex' as that I suppose.
The fact remains that the second largest religion in the world is not going to disappear any time soon.

I'm afraid to say it but without drastic actions, we will never stop terrorism

One solution might be to educate.

Start our own army of terrorist. Cant beat'em
Join'em
Im jus say'n

greater security at events, harsher penalties for convicted terrorists (don't know if that is possible or not), burn all Korans

Kill Hate!

Truth is not much. ...unless ya round em up once they get on d radar

once they've become radicalized there's not much we can do. we need to focus on stopping our own from falling prey to their recruitment tactics

Stop causing unesessary wars. Stop letting economic migrants pour in. And stop dividing us all. Theres a great start ☺

These people have very specific recruitment tactics. I feel like we should learn to counter those points and raise awareness.

Why does it have to exist :/

Nothing.