Does " against their concessions" refer to "(the western imperialist powers had made concessions...?

Does " against their concessions" refer to "(the western imperialist powers had made concessions in order to have peace with China, but the Kuomintang still decided to attack them)"?

Context:

Anti-Imperialism[edit]
During the Nanjing Incident, the Kuomintang took on the western imperialist powers in China, launching an all-out attack against their concessions in many Chinese cities. Chinese forces stormed the consulates of the US, Britain and Japan, looting nearly every foreign property and almost assassinating the Japanese consul. Nationalist forces killed an American, two Britons, one Frenchman, an Italian, and a Japanese. Chinese snipers targeted the American consul and the Marines who were guarding him, Chinese bullets flew into Socony Hall where American citizens were hiding out. One Chinese soldier declared, "We don't want money, anyway, we want to kill."[2] The Kuomintang forces also stormed and seized millions of dollars worth of British concessions in Hankou, refusing to hand them back to Britain. Britain then decided to give them up.[3]

More:
https://en.wikipedia.org/wiki/Northern_Expedition#Anti-Imperialism