The three articles for Perpetual Peace read, "The Civil Constitution of Every State Should be Republican, The Law of Nations Shall be Founded on a Federation of Free States, and The Law of World Citizenship Shall Be Limited to Conditions of Universal Hospitality (Kant, 1795)." Kant's thesis's premise is that...
The three articles for Perpetual Peace read, "The Civil Constitution of Every State Should be Republican, The Law of Nations Shall be Founded on a Federation of Free States, and The Law of World Citizenship Shall Be Limited to Conditions of Universal Hospitality (Kant, 1795)." Kant's thesis's premise is that peace is only attainable when a formal institution such as a government initiates and maintains the state of peace; the government must consist of free individuals in a republic form guided by a civil constitution.
Keep in mind Kant was writing in the age when monarchies ruled Europe. Kant contrasts the desire of monarchies to institute hostilities against other monarchies with the contra-desire of free humans to avoid conflict and war. The state is continuously in a mode of high alert to go to war, whereas a republic requires the consent of the majority who carefully weigh the personal cost of war as too high.
As to which article, if implemented, changes the American politics of warfare, history offers some clue. Kant's first article, "The Civil Constitution of Every State Should be Republican," is the logical place to begin. The Constitution of the United States is a republic form. In the past fifty years, Americans have witnessed several wars (some ongoing) without Congressional oversight. One can argue as Kant might that the modern republic offers little in preventing perpetual wars from occurring. For example, the United States has ongoing operations in Afghanistan since 2001. Even though in 2014, Nato and the US formally ended combat missions, it is hard to argue with American troops still in Afghanistan that the US is not at war.
The second article says, "The Law of Nations Shall be Founded on a Federation of Free States." Kant would look at the current political state of affairs in the world and indeed conclude that a large part of the world is not based in a federation of free states or nations. The twentieth century and now the twenty-first is replete with examples with wars beginning with incursions into weaker states. Kant might assume the root cause, or reason for so many wars involving virtually every country on the globe, is the assimilation of free states through dictatorships, military coups, theocracies, or autocratic governments. However, this observation precludes the numerous imperialistic and militaristic efforts of democrat republics to advance their political agendas.
"The Law of World Citizenship Shall Be Limited to Conditions of Universal Hospitality" is the third article. In this, Kant proposes the world operate without borders, openly accepting any non-native person arriving peacefully in the nation. The notion of a one-world community where a person may have civic responsibility in a country but has a personal obligation to place the world community first is not new. Several modern organizations—the United Nations being the most obvious—are representative of this ideal.
Kant, to his credit, presents this argument but has no pretense or is not naive to think the notion of world citizenship is attainable. Kant introduces the idea and then provides evidence contrary to what he terms the "inhospitable action of the civilized," drawing particular attention to the "commercial states of our part of the world." Historical and present-day evidence demonstrates nations are far more interested in hardening borders than erasing.
If implemented today, which of the three articles would radically change the US-American politics of warfare as we are seeing them now? Return of the US government's control back to the people and as a true democratic republic offers the best hope. Thus, the first article of Perpetual Peace provides the best hope. Free people, when left to make a choice, generally seek peace over war.