Britain & Mexico
The U.S. fought with Britain and Mexico over the Oregon and Texas territories. The U.S. gained Texas in a war with Mexico but did not gain Oregon through a war. Advocates of Manifest Destiny called for war with Great Britain under the slogan of "fifty-four forty or fight", a reference to the latitude they wanted the US to claim from England. Instead of going to war, the US negotiated with England and the border was established at the 49th parallel.
The U.S. fought with Britain and Mexico over the Oregon and Texas territories. The U.S. gained Texas in a war with Mexico but did not gain Oregon through a war. Advocates of Manifest Destiny called for war with Great Britain under the slogan of "fifty-four forty or fight", a reference to the latitude they wanted the US to claim from England. Instead of going to war, the US negotiated with England and the border was established at the 49th parallel.
The Allied Nations fought against the Axis Powers. This was the United Kingdom, France, the United States, Canada, Australia and Soviet Union. Many other nations also sided with the Allied Nations.
UN-United Nations
The United States fought against the United Nations during World War I and then fought Canada and Emperor Palpatine's droid army after nuking the UN headquarters in New York. The US won.
Argentina and The United Kingdom.
Afghanistan has been in a lot of wars. These include with many Middle Eastern nations as well as the United States.
Lots of nations fought on the allied side of WW1. Some major ones were the United Kingdom, France, USSR, and the United States.
Look at the list of the United Nations; the UN fought there.
Prior to the outbreak of war, the nations of Europe fought political wars over territories abroad.
fought for it