In his 1967 Christmas sermon on peace and nonviolence, the Reverend Dr. Martin Luther King Jr. stressed the interrelatedness of Earth, nations, and all life: 

Now, let me suggest first that, if we are to have peace on earth, our loyalties must become ecumenical rather than sectional. . . . We must develop a world perspective. No individual can live alone; no nation can live alone, and as long as we try, the more we are going to have war in this world. . . .

It really boils down to this: that all life is interrelated. We are all caught in an inescapable network of mutuality, tied in a single garment of destiny. Whatever affects one directly, affects all indirectly. We are made to live together because of the interrelated structure of reality.