Proposed to a students to be more polite and clever in the world of future. The last 20 years we was going to avoid the use of nuclear weapons and maintain an economic power. Without any nuclear weapons, international unions (WTO) could to punish any land for illegal activities by the economic sanctions.
Also this could be made regarding to the certain person who made a violence. For example the government has a huge database about every person and they can control all life(life standard, job...) and in a flat world the government could encourage and punish.
We do the globe like a big nest without catastrophic weapons which could negative affect on our climate, air, water...