While we are working towards eliminating the motivation of terrorism by reforming our international group behavior, we must include disarming terrorists. Therefore let's start with the banning the sale and manufacture of the AK-47.
“It is believed that AK-47s have caused more deaths than artillery fire, airstrikes and rocket attacks combined. An estimated quarter of a million people are gunned down by bullets from Kalashnikovs every year.” (http://rt.com/news/kalashnikov-rifle-ak47-facts-691/)
If we choose to, we may keep as strict a control on the manufacture and sale of this weapon as we do nuclear arms. The elimination of this weapon should be a global goal.