By the first week of April, 1944, tensions among the Allies were heating up. When Eisenhower decided to stop his advance at Elbe River, it let the Soviets take Berlin. In Bavaria, forces headed toward what they thought would be a Nazi final stand. And half a world away, men and machinery geared up for "Operation Iceberg," the Battle for Okinawa. 172,000 troops would meet staunch opposition from the island's fanatical Japanese defenders.