El Gran Capitán.
This is coolbert:
Thanks here to Al Nofi of CIC [CIC # 174 ] through StrategyPage.
"Never attack on ground chosen by the enemy."
-- Gonzalvo Fernandez de Cordoba, “El Gran Capitán” The Battle of Seminara, June 28, 1495
My instantaneous, instinctive, intuitive response upon reading this quote of El Gran Capitán was to think of the Israeli "incursion" into southern Lebanon, 2006.
An attack by the full might of the Israeli army and air force upon the prepared positions of the Hezbollah "fighters" that did not result in the usual Israeli unqualified victory. The "incursion" of Israeli forces did not go well? Was viewed in Israel even AT THE TIME  AS SOMEWHAT OF A DISASTER!
Objectives were NOT fulfilled. Captured [kidnapped] Israeli soldiers were NOT repatriated!! Hezbollah, even when suffering a lot of casualties, emerged with a lot of prestige in the Arab world. NOT what the Israeli military had hoped for! Issues leading to hostilities and fighting in southern Lebanon were NOT resolved but only exacerbated!! A TENSENESS still exists, Israeli and Hezbollah forces preparing for a second round of fighting at any time!?
Attacking on ground chosen by the enemy is intuitively a bad idea!?
Your enemy has made his appraisal of the situation, decided upon defense, and has the INITIATIVE IN THAT SENSE?! In the case of Hezbollah, about 5,000 fanatical fighters have selected ground suitable for defense [southern Lebanon] and improved with multiple hardened fighting positions, connected by a series of tunnel complexes.
Hezbollah "fighters", armed with a seeming inexhaustible supply of anti-tank guided missiles [ATGM] of super-sophistication, WERE able to inflict unexpected casualties on Israeli armor. Casualties that the Israeli CAN ILL AFFORD FROM A POLITICAL STANDPOINT!!
Of the thirteen verities of combat as enunciated by Dupuy, these qualfify in this instance:
# 2 - - "Defensive strength is greater than offensive strength."
"Defense is the stronger form of combat". Defense is easier to do, produces more with less.
# 6 - - "Defenders' chances of success are directly proportional to fortification strength". NOT ONLY had Hezbollah chosen ground suitable for defense, the terrain had been prepared with carefully constructed fighting positions of strength. Hardened and relatively impervious to all but a direct hit from a large caliber weapon or a terminally guided bomb dropped from an aircraft!
The observation of El Gran Capitán was true in 1495 and WILL ALWAYS BE TRUE!!
"Gonzalo de Córdoba (September 1, 1453 – December 2, 1515), was a Spanish general who made Spain the preeminent world military power for almost a century and half. He was called El Gran Capitán ('The Great Captain')"
Along with the essential Sun Tzu, all senior military commanders should carry around a little book just chock full of quotes such as was made by El Gran Capitan? Refer to the book and help them avoid mistakes and unnecessary casualties!? Essentials of warfare that have been true, are now, and ALWAYS will be!?