Ian Stirling wrote:
Jordan wrote:

Sander Vesik wrote:
Yes, because its one of those outcomes of the test they are not going
to promise to repeat, especially not apparently not having finished
the kill vechicle software. Working once through luck in a particular
situation is no guarantee of repeatability.

Generally speaking, a type of weapon becomes _more_ accurate and
capable as it is developed, so I don't see why it would be surprising
for our ABM's to similarly improve in capability. There are some
exceptions (such as the disastrously flawed magetic exploder on our
early-WWII torpedoes compared to the earlier fuses) but such
degradations of capability through development are not the norm.

That doesn't preclude the one success being at a time when the chance of
that success is .1%.

Well, yes, but that would be improbable. We have to go on the basis of
the most probable interpretation of the data from the various tests,
which _seem_ to show an increasing ability to intercept more and more
difficult ICBM-like targets.

We can also use actual battle data as a basis for evaluation. The
early Patriot heavy SAM/ABM, used in Desert Storm, enjoyed about a
25-75% kill rate _per engagement_ (*), depending on one's definition of
a "kill" (**). This was in 1990. It is reasonable to assume that the
Patriot III's currently being used are more effective weapons. One
must, however, factor into this the knowledge that the early Patriots
were engaging SRBM's, not ICBM's or even IRBM's -- which are harder to
intercept.

When one goes from ABM's to energy cannons, the tests of the Air Borne
Laser system in the early 2000's were quite encouraging, which is
probably why they were put into production. The ABL is highly accurate
and lethal versus missiles in the boost phase; less effective against
missiles which have already expended their fuel (for the obvious
reasons). It does put enough energy onto the target to cause
considerable damage through thermal explosion, though.

In general, we can assume that BMD systems will increase in relative
effectiveness until the offense makes an advance, such as the
deployment of an effective decoy or other kind of penetration-aid
system. Fortunately, the enemies we most fear right now, North Korea
and Iran, are technologically more primitive than are ourselves, and we
HOPE (***) that they cannot deploy effective penetration aids (****).

- Jordan

(*) Meaning that multiple missiles may have been launched.

(**) This isn't weaselling; the question is whether you define a "kill"
as "a hit hard enough to knock the missile off course / prevent any
delicate device from detonating" or "complete physical desruction of
the warhead," which is obviously harder to achieve (and not necessary
for most military purposes).

(***) If they do deploy such aids, it wouldn't be the first time that
someone was surprised by the capabilties of an ostensibly-less-advanced
enemy.

(****) But the hope has some foundation in that most penetration aids
either increase the mass of the payload, make the flight profile more
complex and hence likely to fail, or both. It was not a trivial thing
for us to progress from single-warhead ballistic missiles to MIRV's,
which is an advance on roughly the same scale.