No. The "threatcon" levels refer to local security posture of an individual installation. (see here.)
From the site:
THREATCON BRAVO applies when an increased and more predictable threat of terrorist activity exists. The measures in this THREATCON must be capable of being maintained for weeks without causing undue hardship, affecting operational capability, and aggravating relations with local authorities.
Charlie means there's an imminent threat to the base, and Delta typically means an actual attack is in progress or is likely to occur soon.
Thanks