It's very simple. It's an abbreviation of a name, just like if the United States is abbreviated as USA.
Because there is an English abbreviation method, which is to use the capitalization of the first letter of a noun as an abbreviation.
The Chinese abbreviation method is to simplify a word, but it can be expressed clearly at a glance. This is the Chinese abbreviation method.
If the four words "Red Alert" were written as "Lust and Caution", it would be completely confusing, and the name is so nondescript that it would be like watching a pornographic movie. Put four words together. If you want to express it simply, you must highlight its characteristics. Red means red, and alert means alert. Combined together, it can be simply called Red Alert.
For example, when we play the game Warcraft, we basically call it Warcraft for short. Whether or not the word "Struggle for Hegemony" is included does not affect our understanding of the two words "Warcraft".
Looked at separately, they are devils and beasts.
Wherever there are devils and beasts, they must be killed.
If you don’t look at them separately, Warcraft is the name of a fantasy higher animal. Wherever there are Warcraft, they will definitely be killed.
This is the Chinese abbreviation. It is catchy to read, and you can hit the nail on the head if you mean what you mean.