The fallacy of the excluded middle, or the false dilemma, presents a false choice by offering only options A and B when in fact there are also options C, D, E, etc. This is commonly used by warmongers to suggest that there are only two philosophical options in foreign policy: to be a warhawk or to be a pacifist.
This is simply not the case. Wendy McElroy argues:
Even if anti-war arguments could be definitively quashed, it would not mean the arguments of hawks are correct. Those who believe in the propriety of war (or some wars) fall along a continuum. Just war theorists are at one end; they generally apply some version of the guidelines that have evolved since the 16th century Spanish scholastics started pounding them out. At the other end are the hawks; they generally apply a patina of propriety -- e.g. nuns strapped to tanks -- to starting a war and, then, procced as though everything about that war was justified. They may concede a detail here or there, for example, whether or not Gitmo prisoners be tortured, but if a war is said to be "justified" then all bets are off. The reality is quite different.
Read the rest of her interesting discussion on "civilized war," which refuses to target civilians, values neutrality, and praises politicians who use diplomacy to avoid conflict here.