Gettysburg's "Decisive Battle"

Our conviction that only a great battle can produce a major decision is founded not on an abstract concept of war alone, but also on experience.... All fortunate generals, and not only the bold, the daring, and the stubborn, seek to crown their achievements by risking everything in decisive battles. --Carl van Clausewitz (1) IN THIS TIME of military innovation and an increasingly complex strategic situation for the United States, many have faith that technology and new frameworks of diplomacy will make the use of U.S. military force short and conclusive. Current joint and Army doctrine cites the need to use force decisively to gain military victory over opposing military forces. (2) For many, the Persian Gulf war was a new model for battles of annihilation and decisive military engagement. But, what is "decisive battle?" Answering that question could benefit from a historical analysis. One of the most well-known American battles, the Battle of Gettysburg, provides an excellent historical example for studying the link between decisionmaking and the battlefield. Military historians frequently depict the Battle of Gettysburg as one of the decisive battles that marked a turning point in the American Civil War. Gettysburg was a major and significant battle; over 51,000 casualties during a 3-day period are evidence for this claim. Yet Gettysburg is often described as the battle that doomed the Confederate struggle. On the surface, this is a questionable claim. The war lasted for almost 2 years more. What did the "decisive" Battle of Gettysburg really decide? Historians and military leaders often use the term decisive battle without defining it, and such definitions as exist fall into one of three categories. (3) In the first and most widely accepted definition, a battle is decisive if it achieves operational objectives. Such a battle differs from a battle that results in only a tactical victory. A decisive battle often results in a military stalemate or a pause before the start of a new campaign. A second definition states that a battle is decisive only when it ends the conflict by achieving one side's strategic objectives. These battles often lead to treaties that temporarily settle political differences. The last and most exclusive definition states that only battles that directly end the conflict and result in a lasting peace between the belligerents are decisive. Few battles in history can claim this distinction. To judge which definition sets forth the best criteria for the term "decisive battle," we must resolve the degree of decisiveness required. The magnitude of losses appears to be the sole criteria many popular histories use to identify the most decisive battles of all time. Their authors seem to consider only the largest battles and those in which a tactical defeat was total. The important question of what these "decisive battles" really decided is rarely addressed. Yet by looking at Gettysburg, the largest of Civil War battles, and the desired outcomes the two opponents sought, a definition for the term "decisive battle" emerges. A truly decisive battle must decide consequences beyond military issues of tactical importance and operational significance, A decisive battle must directly lead to a rapid resolution of the contested political issues because the results on the battlefield caused both sides to agree that a decision had been reached. The Search for Battle Civil War political and military leaders believed that decisive battles should be sought and that a conclusive collision of armies was the goal of military operations. They believed this because of their experiences in the Mexican War. They also believed in Western military tradition. Decision in battle was still possible. It was the goal of generalship after the Wars of Napoleon. Prussian strategist Carl von Clausewitz said, "Since time began, only great victories have paved the way for great results. …