Because the war on terror is fought in a peacetime atmosphere, treason can be presented as dissent, and you can get away with it. Case in point is the energetic pursuit, and publication, of U.S. intelligence gathering techniques, by the American media. The latest one was the reporting of how the U.S. has been analyzing international bank wire transfers. This apparently led to the capture of several prominent terrorists, especially in Southeast Asia. But to opponents of the war, this is an assault on civil liberties, attacks they consider more dangerous than potential terrorist violence. Earlier scoops revealed to terrorists how the traffic analysis was being used to track terrorist activity.
Again, the threat to civil liberties, relative to the lack of a real terrorist threat, was used to justify what was basically treason in time of war. But the war on terror is not a normal war. There's no country to declare war on, so there's no formal declaration of war. Every war has it's dissenters and opposition politicians criticizing how the war is fought. The unique nature of the war on terror, with much of the action being on the domestic front, has us searching for terrorists among our own population. This leads to opposition groups depicting success against the terrorists (no attacks) as the absence of a real threat. This leads to implications that the government is using the war on terror to establish government intelligence gathering programs that threaten civil liberties.
The absurdity of this is that the intelligence programs that have been revealed involve techniques that have been used before to successfully track down criminals, and have not led to compromising anyone's civil liberties. Indeed, if any government program was misused to persecute an American, the uproar and blowback would be monumental. There are some examples of that, but far fewer of government exploitation of intelligence programs. Criminals benefit far more than citizens suffer. Moreover, many of these techniques were used successfully by the West German government in the 1970s, to deal with an outburst of domestic terrorism. Thus the track record has been that these techniques work, and don't do any damage to civil liberties. Ironically, the German government then shut down the program in the late 1970s, after it had done its job. The reason given was that such powerful tools posed a threat to German liberties. In actuality, there were apparently plenty of politicians worried about their illegal activities being exposed (and many of them have since come to the surface, including links with the secret police in East Germany.) There may be similar fears in the United States, for it is known that many politicians and activists opposed to the war have crossed the line. Some have been caught and punished, and many others probably fear the same fate.
Trivializing the enemy is another dangerous journalistic tactic. Many of the Islamic terrorists are basically amateurs. The bunch rounded up in Miami recently are starting to be portrayed as victims, rather than threats. However, if one or two FBI supervisors had zigged instead of zagged back in early 2001, and the 19 or 20 911 terrorists would have been rounded up. It would have been very easy for enterprising journalists to portray this as an overreaction by the FBI. After all, who could take seriously this plan to simultaneously hijack four aircraft and crash them into buildings? It was all too absurd, and another example of the excessive police power of the government.
Treason aside, these tactics of destruction by revelation, and trivializing the threat, do provide substantial benefits to the enemy. While the most professional and experienced terrorists were always aware of things like traffic analysis and CIA access to international wire transfer data, most al Qaeda activists do not. But now they do, and the implications have been spelled out for them, in great deal, by helpful journalists. This influences future reporting, which will tend to avoid connecting the dots between these revelations and the success of some future terror attack. A sort of unconscious professional courtesy. There is one new element; net based journalists. That includes widely read bloggers and reports like this. But that only keeps the crimes visible, it doesn't do much to punish the guilty, or stop the assistance these traitors are giving to those who would kill them, and us.
These traitors will continue to get away with it. Unless their activities are shown to assist terrorists in a particularly direct and obvious way, scary stories about potential perils will continue to protect those attacking the counter-terrorism effort. By blurring the line between legitimate dissent and active assistance to the enemy, political opportunism has sunk to new lows.