How did the Japanese invasion of Manchuria affect international efforts to achieve world peace?

Mao Zedong refused to appease Japanese aggressors, which increased tensions.

The League of Nations had little concern for Asian politics and made no comment.

The invasion caused International sanctions, causing Western nations to close their ports to Japan.

The invasion heightened tensions in Asia, making Japan a focus of Western nations in the coming war.

The Japanese invasion of Manchuria heightened tensions in Asia, making Japan a focus of Western nations in the coming war.

Explanation:

It is the obvious answer. While the international focus was maintaining piece, the Japanese began a war. Invasions will never be easily tolerated and there will always be countries strongly against it. In that era, specifically, it caused greater problems since Asia was already tense and it didn't become any better with the invasion. Sanctions was too little for what happened.

The invasion heightened tensions in Asia, making Japan a focus of Western nations in the coming war.