This is pure speculation, but even if I'm wrong about Saakashvili basing his decision on bad intelligence, supporters of a more aggressive push for expanding NATO further east now had better remember that the so-called Siloviki (those involved in the former Soviet security and military services) have not all broken ties with Moscow. That means incorporating countries like Ukraine and Georgia in NATO could be the biggest boon for Russian intelligence services since Aldrich Aimes and the Walkers. Is that really what former Cold War hawks want? Nice as it is to be seen supporting democracy in Georgia and Ukraine, let's think intelligently about the costs. After all one of the great successes of America's cold war policies in Europe, as opposed to elsewhere, was the cold-hearted awareness of what America could and could not do to support people opposed to Soviet domination.
For those interested in learning more about the conflict in Georgia and its broader implications, I recommend checking the archives at Josh Marshall's Talking Points Memo for the period Auguest 10, 2008 -- August 16, 2008