Sentence:  In a log jam, where everything is at cross-purposes, there is somewhere a key log causing the trouble. The <WSD>key log</WSD> in the educational jam is the department, and the things which have caused it to make so much trouble are narrow departmental ambition and excessive striving for reputation through the publication of research. 
Meaning of the word marked with <WSD> tags:  The key issue or problem, which if (re)solved, would make the current task easy to complete. The issue around which the whole problem revolves.