Arms race rules, anyone?
As idiot politicians have to be reminded every decade or so, and certain military nitwits above major general rank (where IQs mysteriously plummet as soon as the second star is affixed), you are doomed to lose any arms race in which countermeasures are cheaper than whatever they are countering. An interesting version of this rule played out since about 1960 as the ICBM-vs-ABM race has consumed colossal amounts of taxpayer cash. The late 60s produced the Sprint ABM (extraordinary performance for the technology of the time) which still had nowhere to go as the Sovs loaded up their ICBMs with ever more MIRVs and decoys.
My point? As long ago as Reagan's Star Wars SDI imbecility, engineers were pointing out that it's much easier and cheaper to harden missiles against lasers than it is to produce vastly powerful beams which can track and sustain power-on-target against high speed projectiles. Practical ideas mooted included mirrored coatings; ablative coatings; and even spinning the projectiles so that contact energy was spread across the airframe. Slightly more "active" approaches include such things as nose nozzles to produce a fog to disperse laser beams.
Lasers have their uses in target designation, comms, blinding sensors and the like, but for use (in the atmosphere) as destructive weapons means immensely powerful systems with fearsome abilities in target acquisition—holding a dime-sized spot in the same location on a supersonic projectile in the presence of rain, fog, cloud, smoke, chaff, sparkledust (take your pick) is difficult enough without the projectile itself employing simple countermeasures.
In short, the only people talking up lasers with such optimism are those selling them. Still, they've surely got a willing audience of fathead politicos wielding the taxpayers' chequebook.
Biting the hand that feeds IT
