I do not buy into this paradigm that you have to treat killers with kids gloves for fear of giving birth to more killers, and more virulent ones. They need no help either in self procreation of their kind, or in sustenance of virulence. They seem to have a bottomless fountainhead on that one.
It is better to be feared than loved - Machiavelli
People should either be caressed or crushed. If you do them minor damage they will get their revenge; but if you cripple them there is nothing they can do. If you need to injure someone, do it in such a way that you do not have to fear their vengeance. -Machiavelli
Revenge may be wicked, but it’s natural-William makepeace Thackrey
People who believe that unless they treat their Enemies with Kid Gloves,they would be strengthning the enemy, are delusional of first order. The only natural outcome of an animosity is annhilation of your enemy, or a reproach in case a greater threat lead toconvergence of priorities .This is a natural truth and has been vindicated throughout the history.
Did mass murder of Red-Indians bred new Enemies for USA?
No, Their number has reduced to such a number that they are not a political threat to even a municpality of US.
Did mass deportaion of ethnic Germans from Soviet occupied Europe after WWII?
No, This plan was supported by both Churchill and Stalin in order to ensure that Germany would never have a causus-belli to wage war on Eastern Europe.
Did Spanish Inquisition lead to creation of "more" Enemies?
No, it succesfully converted a muslim province into a Catholic Christian province.
Did forced conversion of Kashmiris by Ghazi Sikandar 'Butshikhan' created trouble for Muslims?
No, Kashmiris hate their own Hindu brethren more than anything.
Did forced conversion/surrender of Pakistani muslims created trouble for Muslims?
No, they hate their ancestors and blood more than anything.
In Indian history, you could take to two different examples and their outcome to understand fallacy of this argument of Kid glove treatment. The one of Ghazi Salar masud and that of Muhammad Ghori.
Ghazi Salar masud ( nephew of Ghaznavi) invaded India after death of his uncle's death. He faced a coalition of Indian kings in battle of Bahraich.In this battle he was defeated and killed. Hindu alliance lead by Raja Sukhdeo gave no quarter in the aftermath of battle. There were no PoW's and all soilders alond with camp followers were massacred. After this battle India was not invaded again for 160 years.
Compared this to Mohd. Ghori. Prithviraj Chauhan,after defeating Ghori in first battle of Tarain in 1192, let him escape to Afghanistan and did not pursued his defeated foe, neither he cleared Punjab Plains from Ghor infestation. Ghori came back after a year and defeated him in second battle of Tarain.
History has proven it time and again that only absolute brutality in dealing with an incorrigible foe pays. Go anything less than full mongol on your foe, you risk your own annhilation.This is the reason that if India as a nation die, it would not be because of Pakistan or China, but because of our resident Sickulars.
India,whenever there was any Empire, remained an undefeated power (except when white Huns sacked Taxila) when it was following aggressive war codes like that of Arthashastra. Once the non-violence ideology took hold after fall of Magadh empire (Harshvardhan was last in line), India was overrun by every Tom Dick and Harry.