germany
Britain, France, Russia & the US are common to the Allies in both WW1 & WW2. They are opposed by Germany in both wars. In WW1 Italy & Japan were both on the side of the Allies, in WW2 they were on Germanys' side. Turkey was on the side of Germany in WW1 & Neutral in WW2. Austria/Hungary was on the side of Germany in WW1 & were also on Germanys' side in WW2, (although it might be said by force rather than choice.) although they were then 2 separate countries.
Germany, Ottoman Empire, Austria-Hungary, and Italy
GermanyAustria-HungaryOttoman EmpireBulgaria
There were many countries that fought with us (on our side) in World War One. Assuming you mean the United States as "us," we were part of the Allied Nations. We joined the war in April of 1917 with countries including Great Britain, Russia and France for the most part. There were many other minor countries on our side such as Japan and Italy. We were against the Alliance of Germany, Austria-Hungary, and Turkey.
germany
The Allied Powers.
Italy and Turkey.
poland,italy,belgium,switzerland
Italy who were originally on the side of the germans who then moved to the side o f the british.
Japan emerged as a world power, but Germany was weak and humiliated
Britain, France, Russia & the US are common to the Allies in both WW1 & WW2. They are opposed by Germany in both wars. In WW1 Italy & Japan were both on the side of the Allies, in WW2 they were on Germanys' side. Turkey was on the side of Germany in WW1 & Neutral in WW2. Austria/Hungary was on the side of Germany in WW1 & were also on Germanys' side in WW2, (although it might be said by force rather than choice.) although they were then 2 separate countries.
Germany, Ottoman Empire, Austria-Hungary, and Italy
Germanys
Germany, Japan, and Italy. Those are the biggest Axis Powers, but there were probably more lesser know countries that fought for the Axis
Lots of nations fought on the allied side of WW1. Some major ones were the United Kingdom, France, USSR, and the United States.
GermanyAustria-HungaryOttoman EmpireBulgaria