&gt; That relies on the fundamental assumption that all criminals will reform their way after a few years in jail and therefore deserve a second chance.<p>First of all, most countries with a life sentence does not have an upper bound (would be silly to call it life inprisonment), but rather a practice with an average sentence of such a length. There is nothing that prevents someone who is consideered dangerous to be kept in prison longer.<p>Second: Those who are kept the longest behind bars are those who are sentenced to psychiatric treatment (It&#x27;s actually odd that you <i>can</i> be sentenced to psychicatric treatment, but you can in many european countries). That is essentially &quot;you&#x27;ll get out when you are no longer dangerous to yourself or others&quot;, which in many cases can be much longer than even the longest prison sentences. Many mass murderes and similar will be in this category.<p>Third: the idea behind short sentences is diminishing returns, the responsibility of the system to reform the convicted (if they fail it&#x27;s their fault) and perhaps most of all - econonomic reasons. Unless I see concrete evidence that longer sentences are actually cost effective for keeping me safer, I&#x27;m not going to allow politicians to make such laws.<p>Cost effectiveness is key. One can&#x27;t just argue that longer sentences automatically makes the streets safer, since it costs a lot. You have got to compare, dollar for dollar, with the effect spending the same money on (for example) Police, Drug treatment, Education, Job creation, ...<p>So the fundamental assumption is not that all criminals will reform, but that most will, others will at least reform enough to not be <i>dangerous enough that the cost of keeping them in prison is worth it to society - the money can be better spent elsewhere</i>.