That chart does not at all show that it follows South Korea! It is massively behind and has suffered a debilitating famine in the 90s. That on top of the spurious data collecting in North Korea that probably skews those numbers.
The people against sanctions want countries around the world to be forced to trade with North Korea. We don't have to be forced to trade with anyone. Free trade is earned, not a right for all the dictators of the world.
The way US sanctions against countries work is when we sanction a country, we also sanction any other country or entity or person who passes money or goods in return for money or goods from the targeted country.
It's not simply "We've decided to not buy and sell goods from a certain country."
What really happens with US sanctions is the guys we sanction all decide to band together with each other and to oppose and hate America, and eventually withdraw from using the US Dollar, reducing the US's influence. That may be good or it may be bad but its definitely not what the US has in mind when it sanctions a country.
By "a period in the nineties", you mean "since the nineties", right? So basically for the past 35 years North Korea has been heavily lagging in life expectancy.
Another way to put that is it's been 75 years since Korea split, and half that time North Korea has been much worse than south Korea.
Let's not even get into what that chart would look like if humanitarian aid wasn't shipped during those famines.
In that chart I see one clearly identifiable famine, after which the life expectancy started rising again. Can you perhaps take a copy and mark out the other famines?
North Korea infamously refuses foreign aid, do you have a source that describes more in detail the aid you're referring to?
Life expectancy in the northern portion of Korea was higher than in the southern portion up until the point the US bombed 2/3 of all buildings in the northern portion.
https://en.wikipedia.org/wiki/File:Life_expectancy_in_North_...
Is that to be expected with frequent famines?