Crispin Burke points out that the structure of defense blogging is evolving:
Contrary to what Tom Ricks laments (and Automatic Ballpoint echoes), I don't think that milblogs are waning, per se. Sure, total posts have slowed down, but many milbloggers are turning to Twitter for day-to-day interaction, link sharing, and up-to-date coverage of fast-moving events, such as last year's "Rolling Stan" incident, or the recent demonstrations throughout the Middle East. And while Twitter seems to have supplanted the shorter posts, many milbloggers have turned to guest-posting in larger publications.
There's another dynamic at work here too. The defense/foreign policy blogosphere, in contrast to the larger political blogosphere has always been tiny. Even the most popular defense blogs get a fraction of the hits that domestic political blogs do, because defense and foreign policy issues---always issues of narrow interest--are often discussed in a (comparatively) nuanced and dense style that requires some knowledge and/or experience to understand and critique.
Thus, it isn't surprising that a lot of conversation is less directed necessarily towards blog readers and more among blog writers and interested academics and practitioners who often comment on blog posts. Much of this conversation occurs in forums such as Twitter and Facebook rather than blogging itself. Some of the most spectacular blog disputes of the last year or so are incomprehensible without doing forensic analyses of Twitter exchanges.
To make an analogy that Alex Olesker of i-Con might appreciate, reading defense blogs without Twitter is like trying to pay attention to the rap game while completely ignoring the mixtape circuit.