Settle disputes and build world peace by basing international relations on binding world law.
Stop active wars by enforcing a ban on violent conflict. Disputes should be resolved in a court of law.
Perpetrators of war crimes should be put on trial before a world court, such as an empowered International Criminal Court. 
Active conflicts should be settled by the parties before a court of law, whose decisions would be carried out and supervised by international peacekeeping forces.
International quick response teams would ensure a successful and efficient humanitarian response in times of crisis.
Direct accountability of national governments to world law complements and supports their accountability to their population and provides a peaceful path to ensure good governance.
Stabilize relations between neighboring communities by facilitating compromises to competition over territory and resources and by instituting truth finding and reconciliation practices.
A world federation, unlike arms control treaties, would eliminate the competition for strategic advantage that is a key driver of the development of new weapons of war and a source of conflict. International peacekeeping forces and investigators under direct control of a representative global parliament could enforce a prohibition on weapons of war, especially for weapons of mass destruction and weapons based on emerging technologies.
Resources, knowledge and lives not spent on the military could be put to more productive use. Violence costs the world over a tenth of the annual economic output.  With less military spending there would be more than enough money to provide equal opportunities to all, further stabilizing peace.
Establish an effective, global rapid reaction force for peacekeeping and humanitarian aid, working under and enforcing world law.
National militaries could be retrained, repurposed, and combined for a global peacekeeping force, operating on the basis of a world constitution. This allows a significant reduction in the overall manpower and cost of the defense sector.
A global peacekeeping force under the command of the world parliament would ensure that aggression cannot be initiated unilaterally by any nation or group. The peacekeeping force would further be balanced and complemented by law enforcement at national and local levels, and would over time become redundant.
By cooperating with neighboring countries and the rest of humanity through a world federation, nations would build the peaceful habits that address the root causes of conflict through diplomacy and collaboration before conflicts ever have a chance to escalate. Resource sharing agreements and social, political, and economic cooperation at the regional and global level would keep war in the history books for everyone.
 International Criminal Court
 Global Peace Index, 2020