If there is a credible threat, then it makes perfect sense to close an Embassy for a day or two while law enforcement and intelligence assets attempt to collect more intell and hopefully neutralize the threat. It also allows time for the host nation to increase local security measures around embassy row (a temporary surge). Closing Embassies based on credible threats is a long and prudent practice, and we shouldn't confuse closing an Embassy for a day or two as pulling in our fangs. Embassies are not security outposts, they're diplomatic outposts. What would be foolish and unacceptable is to open the Embassy when we have credible threat information that results in the needless deaths. That is simply empty bravado. Ambassador's don't make the call to close Embassies lightly, so I think unless the facts indicate otherwise we should trust their judgment.
Precisely! One particular internet commando claimed the President was "surrendering to AQ." While his was an attempt to start a political food fight, it displayed a basic ignorance of some pretty standard security principles.