That does not logically follow from any point you've made. Preservation of something does not legitimize its theft.
If there were no Opium Wars, there would have been no Nine-Power Treaties, and thus the Qing would not have fallen, and thus Mao and the CPC would not have eventually gained control over China, and thus the Cultural Revolution and the Four-Olds Campaign would not have happened?
I am saying it's not legalized.
https://en.wikipedia.org/wiki/Tone_policing
The commenter was angry, but I understand his anger. I can see how even the slightest hint of it in sharing my personal experiences can trigger negative responses from other people, but it also helps for you and others to be sensitive to the trauma that many others (and our families) have lived through.
If I go to your house and beat you up, you have every right to call the police on me and they should be able to throw me in jail, and keep an eye on me until I've reformed my ways. However, this doesn't mean you can go to my house and start stealing all my things: just like any other immoral act, as you point out, one crime doesn't absolve another. This should apply even if you're a policeman.
Accordingly, the USSR should not have seized Kaliningrad, Stettin, and Silesia. Don't you think those territories should be returned to Germany?
If you come to my house and beat me up and loot my stuff, and then burn most of my house down, but I survive, and then a mob of poor people came by and then destroyed other artifacts in my house, do the actions of the mob of poor people absolve you, the original looter?
Does it complicate or simplify things if you, the original looter, also sold opium to the mob of poor people?
(And this assumes that art is like furniture. Hold my beer...)
Here's a 2014 paper on the history of the scroll, including a fairly detailed section on the conservation & restoration efforts since the piece arrived at the British Museum.
The trade off between this method and keeping the scroll in unmounted silk form was between having a more stable backing for the scroll itself to aid in preservation at the cost of removing the scroll's ability to be bent.
The concern for this scroll specifically was that this scroll was unevenly decayed, had numerous repairs in the past and constant continuing repairs would be needed to mitigate wear and tear - frayed silk ends were already an issue. The standard method of dealing with this issue is remounting, and evidence indicated this scroll had been remounted numerous times in it's history.
The museum decided to affix the scroll and apply a form of sealant, after remounting the edge silk sections (which they literally brought experts over from asia to do). This was done to remove the need to repaint and splice sections in (which was the traditional method of maintaining the piece, but which obviously changes it over time) and mitigate future damage to the piece.
TLDR: just read the link I posted.
Does that legalize the current status quo that what are inside the non Chinese museums have all their rights and good will to keep what their ancestors robbed from China?!
Please speak you thoughts clearly.