hahahahh NK is hardly a threat .

Yeah sure what about 10 years from now when they sort out some of the teething troubles with their Long range Missiles ?? Would you rather wait for NK to have a missile ready and hold you hostage to respond to a threat ?? The current system in its current state cannot deter against even a 20 year old Russia Missile attack , or a chinese barage simply because it hasnt been designed to counter those mass threats.

Israelis have spent billions and lot of PAC-4 input to make the Arrow anti missile system but it politically guarantees a scud hit not a real guarantee

I really couldnt find a lot of info on PAC-4 but the Arrow system missile isnt in the legue of the PAC-3 missile but is more in line with the adv PAC-2 missile because it uses a warhead and has greater range , unlike the PAC-3 which is basically a H2K missile . It is true that the arrow is unproven in combat however in tests it has done relativly well , both Isreail and the US have poured in billions into this project . The ADv PAC-2 and PAC-3 did a good job OIF by engaging threats early and at greater altitudes ( the distance of 50-70nm wasnt great in reaction time as opposed to a lot of time for BM comming from NK etc) but at the end of the day what is going to prevail and be a better system is using THAAD , PAC-2 , PAC-3 , AL , AEGIS etc etc to get you a very high probability and give your system a chace to kill the vehicle at all its stages of flight.