It's called 'pillage', long accepted practice for the victorious troops to avail themselves of the material goods of the enemy.
In fact our own US Old Soldiers home in D.C. was started with a generous donation from the residents of Mexico City, in lieu of pillage during our last unpleasantness with them.
And during the British invasion of Vichy Madagascar during WW2, the Royal Marines pillaged the headquarters of the French Army.
Of course in the spirit of Allied Cooperation, the Royal Marines allowed the Frenchies to come and get their stuff. You know like the sash's and medals, bidets and other personal property of the French Army Officers.
Of course to avoid mix up, the brass themselves had to come and get it, not their Aides de Camp ;^)
History records the French left in tears.
But it did establish who the Alpha dog was.
I think the Chinese view is that pillage is only acceptable when they're doing it at somebody else's expense. The idea that some foreigner might do it to China is an insult to finely-tuned Chinese sensibilities.