Smart weapons know where the target is and sell us the myth of no collateral damage. The same promise comes from footballers who tell us they can jump in with both feet without maiming the opponent.
Vincent Kompany thought he could do it. So did Glen Johnson. In they both went, like Cato from the 'Pink Panther' films surprising Inspector Clouseau as he comes home from work.
Neither caused a scratch to Nani or Joleon Lescott, respectively. But would you trust an airborne missile?
This week we have seen Kompany sent off and banned for four games for his jump at Manchester United's Nani and Liverpool's Johnson escape any kind of punishment for his arrow-leap in the direction of Kompany's team-mate, Lescott, in Wednesday's Carling Cup semi-final first-leg at the Etihad Stadium.
Inconsistency is the obvious red rag to football's bull. Kompany was glumly imprisoned in an executive box, while Johnson remains free to go about his work.
As ever we get lost in a fog about which jump was worse and who said what to whom, while the principle on which the law is based is obscured.
Every time the whistle toots there is a tension in the English game between the old island heritage of blood and guts and the modern yearning to see something closer to ballet. We want it both ways: thunderous collisions and David Silva-esque artistry.
Finding that harmony is tough and we can all cite areas where we see imbalance. One is in the penalty box, where any kind of defender-on-striker contact is now considered reason enough for the forward to hit the deck.
This has bred a whole culture of deceit in which the striker encourages the defender to touch him with the end of a toenail to justify the subsequent tumble. Too many commentary box experts are going along with this sophistry.
"There was contact," they say, as if the attacking player has no moral obligation to stay on his feet. But this is subtle, moral-maze material compared to the simple issue of players leaving the ground and arriving at the contact point like human torpedoes.
Chris Foy flashed a red card at Kompany. Lee Mason did nothing about the Johnson challenge. One response probably shaped the other. Mason will have watched the Kompany imbroglio and perhaps decided subconsciously that he was not about the expose himself to a similar trial by TV.
Either both were red-card offences or neither was. And let's go for both, because if you study footage of the most infamous two-footed tackles you will see a level of reckless endangerment that could put a victim in hospital or end a career.
Examples, old and new, would be Kevin Nolan on Victor Anichebe or Steven Gerrard on Everton's Gary Naysmith. The Fernando Torres leap at Mark Gower of Swansea City fits into the category of karate lunges where the recipient is off to the side of both sets of raised studs and therefore supposedly safe, however bad it looks.
You know what comes next. It's the 'he-won-the-ball' defence. Both Johnson and Kompany could justifiably claim as much, but neither complied with the current criteria for the essentially dangerous act of leaving the ground in the tackle.
Referees are meant to look at the speed and intensity of a challenge and ask whether both soles are off the turf. Then they ask whether the tackler is out of control (ie can he change his course of action). Johnson and Kompany fail on at least three of these counts.
Philosophically, plenty of us worry that football is being emasculated. A deeply rooted voice wants the game to be a test of strength as well as skill. But these combative urges are easily quelled by pictures of feet pointing the wrong way after irresponsible challenges.
The sickening injuries to Eduardo and Aaron Ramsey of Arsenal should have been a watershed. Nobody could have studied those images and argued for the eye-popping machismo employed by lesser teams to nullify more graceful opponents.
The advance made by Kompany's tackle was to remind all players that airborne interventions will not be tolerated. The leniency towards Johnson reversed that progress in a moment of weakness by Lee Mason.
Instinct drives them to jump in like this, and sometimes malice. Leaving the ground enables the tackler to arrive faster and 'clean-out' the ball.
But it's not for players to decide whether they can make these Cato jumps without hurting opponents whose limbs are probably planted when the missile hits the ball.
If you tolerate this then your ankles will be next. (© Daily Telegraph, London)