Short answer: Reports of Japanese attacks on civilians affected international relations, but some of the most internationally significant reports came before the Nanjing Massacre.

Prior to 1931, Japan's colonization of Hokkaido, Okinawa, Taiwan, Korea, and Micronesia had all been "legal" in the eyes of the international community. The Manchurian incident, the setting up of the Manchukuo puppet state, and the invasion of China proper in 1937 were not viewed as legal, and caused heavy international criticism. The criticism of the invasion of Manchuria prompted Japan to withdraw from the League of Nations, and most countries refused to acknowledge Manchukuo, but more concrete actions against Japan were limited.

Japan's movement into China and the well publicized violence of those attacks prompted much harsher outcry. Even before the Nanjing massacre, famous photos like ["bloody saturday,"](http://en.wikipedia.org/wiki/Bloody_Saturday_(photograph)) (sorry, wiki) taken during the invasion of Shanghai started to turn Western public opinion firmly against Japanese expansion. This outcry, along with political concerns, led to a US Moral Embargo in 1938, halting shipments of aircrafts, related equipment, and bombs that could be used on civilians. This eventually expanded in 1939 to include airplane fuel. From that point on, the US continued a policy of steadily increasing economic restrictions in an attempt to force Japan to stop.

The US strategy fundamentally misunderstood the Japanese leadership's thinking on expansion. Rather than encouraging them to stop, the gradually tightening economic restrictions confirmed in the minds of the Japanese leadership that Japan's independence, security, and very survival depended on securing territory that would make them economically independent from Western nations. Indeed, as they ran out of the raw materials needed for the military and military industries, they began to consider even more drastic measures to secure resources. This continued search for economic independence was a major factor to Japan's decision to expand into Southeast Asia and other Pacific islands - attacking Pearl Harbor and officially starting the Pacific War in the process.

EDIT: As far as the places you mentioned specifically are concerned:

• The Koreas - There was no Korean state at the time. Korea had been legally part of Japan since 1910, and Korean people would have been seeing the same pro-Japanese propaganda that people in Japan saw.

• Vietnam was under French colonial control, and called Indochina at the time. I'm not sure what reactions the Vietnamese people had, but the French joined in criticizing the Japanese. Later in the war, when Japan invaded Indochina, regular people's reactions were mixed, some seeing the Japanese as liberators who helped them throw off the French, others seeing them as violent conquerors.

• Taiwan had been under Japanese control since 1895. They, like Korea, would have been seeing pretty much nothing but pro-Japanese propaganda

• Indonesia was under Dutch colonial control. The Dutch reduced oil sales to Japan, making them more dependent on the US. The local Indonesians had mixed reactions when the Japanese eventually invaded, much like the Vietnamese.

• Russia had a long history of fighting with the Japanese at this point. I'm sure they criticized Japan, but I'm not aware of any actions taken as a result. That might be my general ignorance of all things Russian, though.