P.S. That map in my previous post is from the wikipedia article on the Russo-Japanese War, and the reddish areas represent what was historically "Manchuria."

The Trans-Siberian Railroad passed through the city of Harbin (in the dark-red area) on its way to Vladivostok, and Japan offered to let Russia keep "Northern Manchuria" as far south as Harbin (thus preserving Russian rail access to Vladivostok), if Russia were willing to let Japan have all of "Southern Manchuria" (including the Dalian peninsula, and Port Arthur). Oh, and the Japanese also wanted the entire Korean peninsula, too.

However, Vladivostok's harbor freezes in the winter, while the Port Arthur harbor is usable year-round -- so the Russians had no interest in Japan's "peaceful partition of Manchuria."

And so, in the face of such unreasonable stubbornness from the Russian side, the peace-loving Japanese had no choice but to launch a sneak attack on the Russian Navy at Port Arthur.

(American historians today might say that Port Arthur was a "beta test" version of Pearl Harbor, while Russian historians might say that Pearl Harbor was "Port Arthur 2.0")