You see, havnig the really smart people get together and agree to outlaw guns will absolutely work.
As an historian, I know it will work because the Kellogg Briand Pact of 1928 worked so well.
You see, the Kellogg Briand Pact, also known as the Pact of Paris, outlawed war. Just about every nation on earth signed it, with France, Germany and the United States the first ones to ratify it.
Notice that we have had zero armed international conflicts since that 1928 pact.