All the finger-pointing about 9/11 would do some good if it led to changes in what our spy agencies are allowed to do.

The CIA and the FBI have been getting a lot of criticism that they did not do more to identify the 9/11 plot in detail and then take steps to prevent it. This is ridiculous. The agencies did have vague information about threats to the United States from Islamist extremists. But so what? What could anybody have done about it?

What if the government had reliable information that Islamists would attack the United States in 2001? Could it have barred all Muslims from entering the country that year?

What if the information had been more detailed - that the attack would involve hijackings in September? Ground all planes for a month? Bar all foreigners from flying in the United States? Specifically ban Muslims or Arabs? Imagine the howl in the media about government paranoia, about racism and religious prejudice. It would have been impossible.

The only feasible preventive action would have been to learn the exact identify of the hihackers and to arrest them. But despite all the warnings, despite al the attention we now learn the terrorist threat received, this information could not be obtained.

One thing is now clear. The CIA had a good idea as early as the mid 1990s that al-Qaida was a threat to the United States. If the agency had been stronger, it might have been able to do something about that, such as hunting down the leaders of that group and eliminating them.

The Church Committee in the 1970s took care of that, as did subsequent restrictions imposed on operations abroad, especially assassinations. We made sure that the CIA did not do anything that would be embarrassing to it or the government if it came out. Finding Osama bin Laden and getting rid of him certainly would have come out sooner or later, so the agency could not even think of attempting it. And it would have been illegal anyway. We can't expect our spy agency to try to protect us if we threaten agents with jail if they succeed.

The main thing that should come out of the 9/11 inquiry is a decision to rebuild the undercover capacity of our spy machine and to give it the authority to act when action may save American lives. (hh)