Anglos are the people in the anglosphere. The term is often used as shorthand for "US+UK interests". It's useful because of the frequency in which those interests and actions align.

The example of the word "German" is amusing because it's kind of coincidental. There used to be more "German countries", and if unification in the 19th century had gone differently, we might still have use of a term for the collective actions of those countries. See for example the Austro-Prussian War, also known as "the German War."