Even the ultimate aim of comtemporary warfare, the political object, cannot always be seen as a single issue. Even if it were, action is subject to such a multitude of conditions and considerations that the aim can no longer be achieved by a single tremendous act of war. Rather it must be reached by a large number of more or less important actions, all combined into one whole. Each of these separate actions has a specific purpose relating to the whole.
Here we are looking at the political object and its supporting military aim as being close together. The applicability of the military instrument is something of a sliding scale which increases the more the political purpose and the military aim are the same. This tracks along very well with the ideal type of absolute war. At the same time this sequence of actions/decisions is very much tied to the specifics of the political purpose and how the phenomenon of war acts upon/changes/develops it. So we have a very basic concept of contingency here, that being a sequence of purpose-driven actions/decisions being made over time and being influenced in turn by a complex ever evolving environment.
The concept of contingency as connected to the general theory does not end there however, and by referring to affinitive Weberian concepts can be even expanded upon.