It is critical to understand the political objective or aim for which the war is being fought. These aims can be offensive, such as seizing a piece of a neighbor’s territory, or defensive, meaning holding what one has. This gives us a firm analytical foundation and the why of the war. One must understand the value each combatant places on the objectives because this helps determine the nature of the war, how long it will be fought, where, and at what cost. But we must remember that the objectives can change. Sometimes this is good. Sometimes this is bad. Leaders must understand when this happens and the effects, because changing the objective means you have embarked upon a different or even a new war and thus changed its nature. For example, the US changed from a limited to an unlimited objective during the Korean War when it decided to destroy the North Korean regime and unify the peninsula. In Iraq in 2003, the US fought the war to overthrow Saddam’s rule – an unlimited aim – but was soon fighting to prop up the new government it had established – a limited, defensive aim. The political aim determines everything.

All wars are fought under constraints. Wars for limited aims generally suffer from more numerous and intent constraints because the value of the political objective sought tends to be lower, and thus states will often do less and pay less for a shorter time. The most important constraints are the value of the enemy’s political objective, time, internal public opinion, the international political environment (which usually means third-party nations with an interest in your war), geography, and the military means (which includes nuclear weapons). Military and political leaders need to understand how these constraints affect their ability to fight and win the war, and they must also determine whether the constraints are actual or self-imposed, and, if they are self-imposed, whether or not they are wise. The constraints are examined via examples from the Korean, Vietnam, and Iraq Wars.