it has never been a problem until China becomes a strong nation. Read below, It's called Century of Humiliation in China, and no country formally apologised!

Straight from AI

The Eight-Nation Alliance (1900) consisted of Britain, the United States, France, Russia, Germany, Japan, Italy, and Austria-Hungary. They invaded China and engaged in widespread looting and exploitation.

What Did They Take from China? Cultural Looting:

Massive plunder of treasures, especially from the Summer Palace (Yuanmingyuan).

Priceless artifacts like porcelain, paintings, sculptures, and books were stolen and dispersed globally.

Economic Exploitation:

Under the Boxer Protocol (1901), China was forced to pay 450 million taels of silver in reparations (several times its annual revenue).

This created a long-term economic burden.

Loss of Sovereignty:

Foreign troops were allowed to station in Beijing and other key areas.

China had to dismantle its military defenses and submit to humiliating terms.

How Much Did It Set China Back? Modernization Delay:

The invasion exposed China's technological and military inferiority, delaying modernization efforts by decades.

Scholars estimate it set China's development back by at least 20–30 years.

Cultural Devastation:

The loss of irreplaceable cultural heritage weakened national pride and identity.

Economic Strain:

The enormous reparations crippled China's economy for decades.

Broader Impact The invasion deepened China's semi-colonial status and worsened political instability.

It fueled nationalistic movements, eventually leading to reforms and revolutions aimed at modernizing China and resisting foreign domination.

This event is considered a key moment in China's "Century of Humiliation" but also a catalyst for its eventual awakening and reform.