Since World War II the US has believed that maintaining a favorable balance of power in EuroAsia is in America’s interest.  To ensure that balance of power remains favorable, the corollary tenet has been the need to have forces that deter attempts to upset or undermine such a balance.  And given the geographic span of that region—a span which includes multiple oceans and a land mass that covers more than half the world’s time zones—that means having dominant forces, global in scope.  Add the requirement for homeland defense, some minimal presence in other parts of the world (e.g., Latin America and Africa) and an ability to assist in humanitarian relief efforts like in Haiti (2010), Japan (2011) and South Asia (2004-05) and one quickly sees just how large our military must be.  In key respects, the two-war standard is shorthand for ensuring we have that globally-capable force in place.

The two-war standard is also important strategically for when America’s elected representatives have to consider fighting one war.  With less than a two-war capability, it will be natural to want to husband US military capabilities, worrying that a commitment to one conflict might preclude dealing with a potentially more serious challenge elsewhere.   Such caution is not always a bad thing.  However, before tossing the standard aside, we should ask ourselves whether there has ever been a period in which the world has been as prosperous and the great powers at peace for this length of time—and why?