Sen. Barbara Boxer, a California Democrat sponsoring legislation to fit missile countermeasures on commercial aircraft, told the briefing that the cost would be about $1 million per plane with 6,800 aircraft in the U.S. fleet.If you have to ask, you can't afford it. There are two possibilities here. First, the anti-missile technology works well enough that would-be terrorists give up on shoulder-fired missiles and look for other ways to target commercial aircraft. This means paying 7 billion clams just to temporarily up the ante on the terrorists. Second, the technology might be, say, X% reliable. This means 7 billion clams and the terrorists can still succeed 100 - X times out of 100 attempts. Now it's not funny when you have to reduce human life to a number, but any policymaker with the IQ of rock salt is duty-bound to come up with an acceptable value for X before spending the money. (Those who don't meet the IQ qualification can stick with the "if we can, we should" justification. No math will be required.)
Another thought: Would putting these on commercial aircraft be cheaper?