(CNN) Israel faces growing backlash over unprecedented Qatar strike.

You don’t read Intel9 for moral judgments.  You can bring your own scales of justice. The purpose of intelligence is to bring insight or foresight to a problem. The current question: Why did Israel find it necessary to eliminate the Hamas leadership in Qatar, in spite of the egregious violation of diplomatic norms, which may in the short term overshadow the mortality of the Gaza civil population?

Identification of constants of the problem can facilitate, as  with Crime Deterrence; Our Groundhog Day of Slaughter, Part 2. This may involve peeling the problem like an onion, as one constant peels to reveal another underneath.  A political constant may give way to a deeper physical one. For example, Vladimir Putin’s ultimate goal in Ukraine is not a political settlement, but seizure of territory, lines on a map.

A particularly neat example:  CNN Editorial, Meredith McCarroll, Anthony Bourdain listened; Appalachia’s Three Percent. The region has long been the subject of sociological hand wringing. The constant of the problem is a problem of geography, the scarcity of flat land. Poverty and social degradation, hauntingly captured by WPA photographers, stem from a physical reality.  Poverty did not create the hills; the hills created poverty.

With this preamble, a  constant of the Gaza conflict  more basal than human intransigence, reveals: the tunnels, alleged to be twice the size of the tunnels of Cu Chi, with some buried so deeply as to be impervious to most ordinance.  The Wikipedia article, and the book, The Tunnels of Cu Chi,  analogize closely to the undisclosed and undocumented IDF experience in Gaza, where the enemy has a dimension of mobility unknown to the attacking force.

• It is due to the tunnels that estimates of Hamas numbers, and their casualties, vary so widely as to negate confidence.
• After 23 months of conflict, the size of the tunnel network, and the percentage destroyed, are not confidently known.
• By extension, it is impossible, using tactical demolition techniques, to disable the network, or even know if it is possible to do so.
• As long as the tunnel network remains functional, civil control is impossible.
• As long as there is civil population on the surface, Hamas fighters can blend with the civil population to sustain themselves underground.
• When measured in decades rather than years, both sides consider this a fight to the death. This is why, as with Ukraine, the problem  is  one of absolutes, where both sides seek to avoid a negotiated solution.
• If the tunnels were comprehensively eliminated, the problem of Hamas would be reduced to manageable proportions. The tunnels are the constant of the problem.

One could assert that the strike against Hamas leadership is intended to silence a voice that would interfere with the  relocation of the Gaza population. But ghosts often have louder voices than the living, which  implies a more visceral exigency that requires silencing what remains of command-and-control of a government-in-exile.

The tunnels cannot be destroyed by tactical placement of demolition charges, because mapping tunnels deeper than near surface is beyond current technology. Far less knowledge is required with deep explosions of the magnitude to create seismic events. Detonations equivalent to kilotons of TNT can fracture rock strata over a  radius of kilometers, permanently robbing the rock of the strength that can sustain a tunnel. Tunnels cannot be built or rebuilt through fractured rock at reasonable cost.

World  War II use of the earthquake bomb indicates that few, if any surface structures would survive. Evacuation of Gaza City is required. Placing the charges, deploying kilotons of industrial explosives deep underground, requires the near absence of enemy combatants.

Conventional explosives are not the only option. To gauge the risks to aquifers, see Geology, geomorphology and hydrology of the Wadi Gaza catchment, Gaza Strip, Palestine. The Gaza aquifer drains into the Mediterranean, sparing areas inland.