The familiarity of measures of effectiveness (MOE) in many areas of life suggests that in modem society quantification is irresistible. Batting averages, stock market figures, returns on investment, air passenger miles, and countless other common measures serve to distill vast amounts of data into relevant information. The armed services also use quantitative methods to analyze and explain their actions to their leaders, political masters, and the public they serve. Aircraft availability and accident rates, combat readiness figures, unit inspection grades, officer and enlisted performance evaluations, personnel retention figures, and other indicators aid organizational processes and quantify the otherwise subjective black art of analyzing military readiness and organizational health. For better or worse, the interpretation of MOE frequently forms the structure on which senior leaders base their orders. Consequently, the need to carefully select MOE is extreme. On the one hand, measures of effectiveness that adequately distill and accurately reflect reality help decisionmakers make informed, timely decisions. On the other, ill-considered or poorly chosen measures have a multitude of negative effects. In addition to misrepresenting that which they purport to depict (with potentially disastrous consequences), the collection and analysis of inappropriate MOE wastes resources and efforts. This opportunity cost is one most endeavors would be glad to do without. Additionally, military and other organizations tune their behavior to improve the measures upon which they are evaluated, which can result in a host of unintended consequences. Clearly measures of effectiveness are important and should be chosen with care. This article will examine military MOE in the context of coercion, and seeks to answer this question: What are the characteristics of measures of effectiveness that will allow decisionmakers to determine if the application of force is bringing an adversary closer to agreeing to demands? The need to address this question is pressing since it is not apparent that current military metrics help decisionmakers determine enemy proximity to defeat. As an example, during the 1999 Kosovo crisis NATO counted the number of tanks, armored personnel carriers, and artillery pieces destroyed, tallied the number of sorties flown and bombs dropped, and estimated the number of Serbian military and civilians killed. As the operation continued, it became increasingly difficult for many observers to understand how changes in any of these measures appreciably reduced Serbian President Milosevic's determination to continue the war. Even if NATO leadership analyzed other classified measures, the MOE that the military reported to the press seemed to validate weapon performance requirements more than they reported progress toward strategic goals. For instance, analysis of the number of sorties flown might have informed interested parties how well airmen kept their planes flying, but it did not provide a sense of whe ther Yugoslavian leaders were ready to accede to NATO demands. That reported measures did not indicate Milosevic's proximity to defeat suggests a key feature of desired MOE. The fundamental relationship that bedevils MOE as considered in this article is that of causality. To be meaningful, a measure of effectiveness should represent and report on a linkage between cause (friendly military actions) and effect (enemy defeat). Unfortunately, in many cases, this assumed relationship between action and effect is weak, or doesn't exist at all. For example, in early 1999, NATO leaders might have assumed that the destruction of Serbian artillery, armored personnel carriers, and tanks in Kosovo would force Milosevic's withdrawal from Kosovo. If true, the assumed causality would be that Milosevic's ability to remain in power depended on his military, and that by destroying mechanized forces in Kosovo NATO would endanger that strength to such an extent that Milosevic would agree to the alliance's demands. …