clarification on phrase

[sonu_gmat]

....are necessary items of arms, as a pretection of.....
OG says begining the phrase with 'as' is incorrect. Can you please explain this.

Thanks in advance.

[JonathanSchneider]

"as" here would mean "in the role of." Leaving the "as" out entirely is probably preferred. Without the "as," we would simply have "protection" after the comma. The placement of a noun after a comma (except when part of a list) begins an absolute phrase, basically a modifier for some previous object or idea from the sentence. Absolute phrases are a very handy way to insert modifiers correctly, and they appear in several high-level modifier problems in the OG.

Of course, if we still wanted the "as," it would be best to remove the comma before it.