Complex sentence: The author explains how the world's converging energy, environmental, and political stresses could cause a breakdown of national and global order, but that there are things we can do now to keep such a breakdown from being catastrophic.
Split into simpler sentences: The author explains how the world's converging energy, environmental, and political stresses could cause a breakdown of national and global order. He argues that there are things we can do now to keep such a breakdown from being catastrophic.