Why have a terror alert system?

In the last couple of days, we have been treated to the maniacal rantings of Azzam the American and Osama bin Laden on separately released videotapes. The first contained the typical, "streets of America running red with the blood of the infidels," crap that we have heard repeatedly before. That it was in English and clearly directed as an unfiltered message to the American people is different. Only a couple of days later we get a strangely reconciliatory bin Laden speaking calmly and reasonably in common Arabic, not the high chant of his previous tapes. This too is a direct, unfiltered message from him to the American people. Either of these tapes should cause concern, both of them right before the election should be sending shockwaves through the corridors of the military, homeland security and every level of law enforcement. Instead we find out today that the Department of Homeland Security will not elevate the Terror Threat Level from Goldenrod to Salmon or whatever. The point is that 6 months ago, either of these tapes would have led the DHS to raise the threat level. The fact that they wouldn't is evidence that the only standard by which the system is governed is political expediency. The Bush DHS is acutely aware that if they raised the threat level it could be seen as an effort to scare people before the election and decried as "dirty tricks" and an October surprise. However, the fact that the system is not administered in a nonpartisan way means it is sensitive to political manipulations and hence, completely without credibility. What then, I ask you, is the point of having a terror alert system if is not capable of adhering to a consistent standard and triggering specific actions and recommendations for citizens. The whole silly exercise should be scrapped.