Before we are as well what? Deploying anti-ship missiles? Fine, but that is totally irrelevant to the issue of area denial for our ships in Southeast Asia.
We already have the groundwork in place for a very good missile defense system that could combat such a threat. With any carrier group deployment, they are accompanied by Aegis ships (which are being upgraded to the new SM-Block IIA missile). That is a good thing.
Unfortunately, we canceled such programs as the MKV, which would greatly enhance defenses against multi-warhead missiles and larger scale attacks.
I also think you underestimate just how much an impact the presence of a weapon system (even if not fully tested) can have... just look at our initial response to this deployment. We are already thinking about pulling back and limiting our area of operations... all because of a missile that has not been tested or proven to work in the capacity that we think it ultimately will.
Following that line of thinking, the development (and even simply the presence) of a missile defense system that is more capable than our current deployment can have a dramatic effect on the strategies other nations employ to limit our power projections.
We already have the technology in place with our current missile defense system to destroy a missile traveling much faster than Mach 5.
You also have to remember that this missile is not a cruise missile, but rather is going to have to exit the atmosphere and then come back and acquire its target... which makes it vastly easier to shoot down, or even just knock off course (assuming of course the presence of a working missile defense capability)
