That "Missile Defense System" is so lame. It literally does not take a "rocket scientist" to know that destroying a high-speed projectile with another high-speed projectile is nearly impossible.
An excellent analogy for what they are trying to do is this: Imagine there is someone with a rifle at one end of a football field and you are on the 50-yard line. Then you are given instructions to wait for the first person to shoot a round over the field and you are to use your rifle to shoot his bullet with your bullet.
This is exactly what they are trying to do... only the missiles are going several times faster than a rifle bullet!
The only reasonable way to stop a missile in flight is with a directed energy weapon such as a constellation of high power lasers in orbit.
Perhaps you Yanks should reconsider Regan's Star Wars (with lazers) . The leaders of your military seem to be idiots with unlimited resources.
The leaders of our military are generally smart, but they don't have anything (except for 50 year old Sea King helicopters STILL used in combat situations). I think America should give Canada some military foreign aid, like they did for Iraq, the Mujahadeen, and most South American despots.
Another fatal problem may simply be the use of unsophisticated missile technology on the part of the enemy nation.
The United States and the Soviet Union built sophisticated missiles with very accurate aim, thanks to spin-stabilization. The country most likely to use missiles against us, North Korea, has cruder missiles with much less accurate aim thanks to more tumbling warheads. But it is precisely these less predictable missiles that are much harder to aim at with missile defense technology.
I would do just the opposite of what the US is doing.
I would put the interceptors near North Korea, so that if the North Korean missile would be lauched, the US interceptor would be near by just off their shore, and would catch up slowly to the attacking missile (following it towards the US) and creep up slowly behind and finally knock it out, rather than doing what they are doing now, trying to hit a rock with a rock coming in the opposite direction.