Safety questions

Something I've been thinking about a bit.

Since September 11, there has been a significant focus on airport and airplane safety.  The Transportation Security Administration has been formed to help screen passengers, and we're now going to be testing a system of checking bank records and credit reports (among other things, potentially) to ensure that everyone getting on an airplane is "safe" for flying.

Concern about air safety is certainly valid, and we do need to try and prevent terrorists from being able to take over our planes and crash them into buildings, or whatever else the may have in mind.

What bothers me, though, is that when you look at air travel in general, there is still a greater risk that a plane will crash from mechanical malfunctions or human error as opposed to being taken out by a terrorist act.  Yet despite all of the airplane crashes we've had over the years, we've never had the kind of focus on making aircraft themselves, and the personnel and crew who maintain and fly the planes, safer, that we now have about the possiblity of terrorism.  There's no denying that what happened was one of the most horrific acts ever commited - but in terms of overall safety issues, there are greater dangers than terrorists that aren't being given anywhere near the same kind of consideration.

By the same token, following the Oklahoma City bombing in 1995, even though we knew it had been commited by white supremacists, using a rented Ryder truck and a bomb made from fuel and fertilizer.  Did we, as a country, establish any kind of systems to help identify potential white supremacist terrorists?  Did we take any steps to make sure that fertilizer and fuel wouldn't fall into the wrong hands?  A rented vehicle was also used in the first World Trade Center bombing, but we don't seem to have put any procedures in place to help make screen who we allow to rent trucks.

It just seems curious to me that so much effort is being made to prevent terrorism aboard airplanes, but we have never done so much to prevent accidents due to other causes, or terrorism that takes different forms.  It suggests that there may also be another agenda at work, though I'm not sure what - and I hate feeling like I'm getting more cynical and suspicious all the time.