Progress was deceptive. When the balance wavered, Russia and China sent in more supplies to the North, refreshing its strength. The low morale deduced from prisoners was a misinterpretation of the stoicism and fatalism of the East. In the American forces, short-term one-year tours of duty, intended to avoid discontent, prevented adaptation to irregular jungle warfare, thereby increasing casualties since the rate was always highest in the early months of duty.
