If they already have the weapons and are in place with orders to use them, there isn't anything the government *can* do, other than annex, raze, and pave a 40 mile radius around every airport.
Or, we can do what we're doing now, and go hunt down the people who organize, train, and order these attacks. Suppressing the regimes that might sell such things works well too as these things have a limited lifespan.
"If they already have the weapons and are in place with orders to use them, there isn't anything the government *can* do, other than annex, raze, and pave a 40 mile radius around every airport."
That's just a defeatist attitute, if there are MANPADs out there and unaccounted for then we should be searching for them, we should install systems on commercial planes that at least give them a chance of evading the missles, I'd rather some chance than no chance at all.
heck a $11 billion can be misplaced in a typo in our budget and it would be a good lil infusion into American Tech industries, no outsourced China or India company can do that kinda work.