The free flow of people across borders is not to be confused with the free flow of goods across borders. Free trade is a positive-sum game. Contrary to illegal immigration, it is always invited, consensual and hence mutually beneficial to the parties involved.
Working with the UN's diplomacy and development arms, we can prevent minor differences from escalating into wars. When conflicts do break out, UN peacekeepers should play a role in defusing and settling them. Without giving up our sovereignty, we can help the UN with better training and better command and control in order to develop more effective peacekeeping forces.