DO we have sufficient technology to shoot down missiles? Like Israel has been doing?
That is a very complicated question. We certainly have the ability to shoot down SRBMs such as the SCUD, but IRBMs are an order of magnitude more difficult to hit, and ICBMs an order of magnitude more difficult than that. The issue comes down to speed - to get longer ranges, you need a greater suborbital entry velocity, which (for a missile) translates directly into a higher reentry velocity. An RV from an ICBM can literally outrun a conventional explosion - the blast wave and shrapnel from an exploding missile warhead will not be fast enough to catch it, which means that there are only three ways to take one out. Either you need a direct skin-skin impact (extremely hard to do at those speeds - hitting a rifle bullet with another rifle bullet is an
easier feat, although computer control helps), an explosion placed in front of the missile (almost as difficult), or you need to use a nuclear-tipped interceptor (which has obvious political problems). The absolute latest version of the Standard Missile fired from Navy AEGIS ships, the SM-3 IIA, has been tested with moderate success against simulated IRBM attacks, but not against ICBMs, and the known simulations did not take MIRV systems or decoy warheads into account. That's why Star Wars put so much effort into energy weapons, which are much easier to hit with, but the power levels needed to hit an ICBM are right at the edge of what we can do today.
The only assured chance of stopping one, even the sort of chicken-wire and bondo type a country like NK would be able to put together, would be a nuclear first-strike at the launch sites.