Arizona Declares Peace

Grudgingly, Arizona last week called off a 22-year-old undeclared war against six sister states. The armistice ended a conflict fought in the heights of the Supreme Court, on the desk-strewn plains of Congress, and on the banks of the Colorado. The weapons in this war had included machine guns, set up in warning but never fired. At stake since 1922 had been the use of the Colorado River, whose waters can make green irrigated empires out of sunbaked cactusland.

The Colorado knifes its way from headwaters down the Grand Canyon and out...