How were the countries of Europe and Asia affected by the
spread of German and Japanese imperial power?

The European countries were effected by the expansion  their colonies and home territory.

Explanation:

The Japanese expansion in the pacific hurt the interest of many European powers of the time which had set up their colonies there.

This includes:

The British in Manchuria , Burma and Indonesia

The French and the Swiss in the East Asian Islands.

It was the expansion of Germany that led the European powers like Poland and Russia to be on alert too as they were expanding into the home territory of these nations and would have gone further too.

The Germans wanted to take over

France, Belgium, Poland, Ukraine and their own neighboring nations.

me on my last question.