The Battalion CP had reason

[GoodTaste]

About 500 yeards south of the engineers, Major Myers held a defensive position with his remaining force of about two platoons. The Battalion CP had reason to believe that the oputposts on East Hill would be relieved shortly by George Company, with the 41st Commando in perimeter reserve.
Source: The Chosin Reservoir Campaign

What does "CP" stand for? Commander Post? But a post is a post, not a person who can reason.

 

[Skrej]

Command Post. It's the location or position where a military unit is commanded from. For 'post' see noun definition #3.

 

[GoodTaste]

For 'post' see noun definition #3.

It says goalpost (one of usually two vertical posts that with or without a crossbar constitute the goal in various games). It has "reason"? I still don't understand.

 

[5jj]

Scroll down to [FONT=Playfair Display, serif]noun (3)[/FONT]

 

[GoodTaste]

OK. The post refers to "the place at which a soldier is stationed", which was what I had in mind at the very beginning.
So the question remains: How does the post "have reason"? Unless it is referred to as a collective noun the people at the post.

 

[jutfrank]

This is an example of metonymy, which is very common in English.

CP stands not just for the place but also for the people at the post making decisions.