Continuous Evolution:

Air Force Space Command’s view—not yet approved by Pentagon leadership—is that the command can “continue to evolve” the Minuteman III weapons system even further into the future. This ICBM evolution would eliminate—for now—the need for more-expensive alternatives, such as starting an acquisition program for an all-new “Minuteman IV” missile, Lt. Gen. Frank Klotz, acting commander, said at a Washington forum. He did not say exactly how long the command now feels the Minuteman III can remain in service.