The problem in the US is the gun culture. Guns are a political statement more than a tool, and any restriction attempt in the name of safety goes directly again

The problem in the US is the gun culture. Guns are a political statement more than a tool, and any restriction attempt in the name of safety goes directly against that statement and will just reinforce and justify more of such "statements". Checks and requirements will only go so far. People can sit through training and forget it the next day if they don't care, which they don't if they just got the gun to make a political statement. Fixing the culture so that people who have no business owning guns stop buying guns is the long-term solution. Then, the only people who will buy them are those who legitimately need them and are interested in safe & responsible firearm ownership.