What is the new understanding that emerged about the death penalty that recently entered the Catechism? What the heck does this sentence added to the Catechism mean?

In addition, a new understanding has emerged of the significance of penal sanctions imposed by the state.

https://press.vatican.va/content/salastampa/en/bollettino/pubblico/2018/08/02/180802a.html
What new understanding?  What significance?  What sanctions? Is this even a complete sentence?
The strange thing about death penalty is that there is no uniformity across the nations on the crimes to which it is applicable, level of the court which is competent to award it, different authorities to whom appeal can be made, and the manner by which the convict is put to death in execution  of the  penalty. India, for instance, is a secular nation where death penalty is in vogue, but is to be awarded in  rarest of the rare ' cases. The convict is given a fair trail, and is mandated to appeal to the Apex Court and then to seek mercy from the President . It takes years together to complete the legal process and to execute the convict, so that nothing is left to speculation that he/she had not been given a fair chance to prove innocence, or to seek a lesser penalty. Unfortunately, that is not the case with all nations across the world.  A visit to the website of Amnesty International is enough to convince one that death penalty which once executed is irreversible, that many innocent people have gone to the gallows for lack of fair trial, and that a number of  nations prescribe death penalty for  crimes such as smuggling of drugs for which other penalties could be given. Now, one cannot expect the draft-makers of Catechism to have  a quintessential summary of all the arguments for and against imposition of death penalty . Naturally, they may have chosen to limit the arguments to a few words viz. ``new understanding.&quot;