>>461
Same author in same book gives some answers to that question:
Japan got her first loans for railway and samurai's salary from the second half of the 19th century. This built up her international financial standing, solvency. However before the war the odds weren't favor her.
>The war was expensive, and the 1 billion U.S. dollars needed to finance the victories of Mukden and Tsushima made Japan an accepted nation state on the world’s financial markets. However, it was hard to secure the first loan, since almost nobody believed in a Japanese victory.
Still she could found the support, where there were ulterior motives, or overlapping interest - to put a friendly spin on it:
>The first money – a 50 million dollar loan – was granted by the banking house Kuhn, Loeb and Co. in New York, where Jacob H. Schiff (1847–1920) had promoted the Japanese case, especially since he hoped to punish the Czarist Empire for its anti-Jewish policies.
When Japan proved to be capable, and gave a reason to believe she can repay her debts, the ball started rolling.
>Subsequent victories bolstered Japan’s position, and more loans were granted at the international finance center in London. In all, 350 million dollars for continued improvements were granted by July 1905.
However the United States and the international financial factors (khm) had an interest in Manchuria. For them it was the open policy what their interest lay in. They did not want either Russia or Japan claim Manchuria to herself, and it seems they used the financial aid as a leash on Japan.
>Despite Japan’s increasing credibility, the financial limits seemed to be reached after the Battle of Mukden, when the Japanese were no longer able to pursue the Russian troops to the north due to a shortage of munitions and the financial implications of continuing the war on a large scale. The remaining money would only last six months, thus peace negotiations were inevitable for the Japanese.
The author quotes a contemporary article from Deutsche Tageszeitung:
Poor Japan! It has not yet killed the bear, but it has already started to cut its fur. The friends of Japan would assist her immensely by pulling the rowdy, belligerent, but promising, nation out of the clouds of victorious excitement to the cold and unemotional earth. Japan has to recognize the real situation and balance of power.

Very interesting!
It would be even better if we could know who were in that "international finance center in London". That would give a more detailed picture how the financing of the war happened.
Also have to note for the quote above:
>the Japanese were no longer able to pursue the Russian troops to the north due to a shortage of munitions and the financial implications of continuing the war on a large scale.