1-21. During large-scale ground combat operations, commanders and staffs deliberately plan and integrate protection capabilities to protect the force, preserve combat power, reduce risk, mitigate identified vulnerabilities, and act on opportunity. Commanders also develop a scheme of protection for the transition of each phase of an operation or major activity. Transitions mark a change of focus between phases or between the ongoing operation and execution of a branch or sequel. Shifting protection priorities between offensive, defensive, and stability operations also involves a transition. Transitions require planning and preparation well before their execution so that a force can maintain the momentum and tempo of operations. A force is vulnerable during transitions. Commanders and staffs identify potential threats and hazards during planning and identify protection priorities during the transition and follow-on operations.